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The notorious growth of lithium (Li) dendrites and the instability of the solid electrolyte interface (SEI) during cycling make Li metal anodes unsuitable for use in commercial Li-ion batteries. Herein, the use of simple sugar coating (α-d-glucose) is demonstrated on top of Li metal to halt the growth of Li dendrites and stabilize the SEI. The α-d-glucose layer possesses high surface and adhesive energies toward Li, which promote the homogenous stripping and plating of Li ions on top of the Li metal. Density functional theory reveals that Li-ion diffusion within the α-d-glucose layer is governed by hopping around the bare sides of the O atoms and along the apparent passages formed by the glucose molecules. Stable cycling performance is achieved when combining α-d-glucose-coated Li (G|Li) anodes with sulfur- and LiFePO

The understanding of nonlinear light–matter interactions at the nanoscale has fueled worldwide interest in upconversion emission for imaging, lasing, and sensing. Upconversion lasers with anti-Stokes-type emission with various designs have been reported. However, reducing the volume and lasing threshold of such lasers to the nanoscale level is a fundamental photonics challenge. Here, we demonstrate that the upconversion efficiency can be improved by exploiting single-mode upconversion lasing from a single organo-lead halide perovskite nanocrystal in a resonance-adjustable plasmonic nanocavity. This upconversion plasmonic nanolaser has a very low lasing threshold (10 μJ cm⁻²) and a calculated ultrasmall mode volume (∼0.06 λ³) at 6 K. To provide the unique feature for lasing action, a temporal coherence signature of the upconversion plasmonic nanolasing was determined by measuring the second-order correlation function. The localized-electromagnetic-field confinement can be tailored in titanium nitride resonance-adjustable nanocavities, enhancing the pump-photon absorption and upconverted photon emission rate to achieve lasing. The proof-of-concept results significantly expand the performance of upconversion nanolasers, which are useful in applications such as on-chip, coherent, nonlinear optics, information processing, data storage, and sensing.

We studied the charge-carrier dynamics in double-layered halide architecture mixed perovskite by pump-probe transient absorption spectroscopy. The excited state absorption shows a 32 times faster electron injection rate in this structure.

The combination of a bulk 3D perovskite layer and a reduced dimensional perovskite layer (perovskite quantum wells (PQWs)) is demonstrated to enhance the performance of perovskite solar cells (PSCs) significantly in terms of stability and efficiency. This perovskite hierarchy has attracted intensive research interest; however, the in-depth formation mechanism of perovskite quantum wells on top of a 3D perovskite layer is not clearly understood and is therefore the focus of this study. Along with ex situ morphology and photophysical characterization, the time-resolved grazing-incidence wide-angle X-ray scattering (TS-GIWAXS) technique performed in this study provides real-time insights on the phase-transition during the organic cation (HTAB ligand molecule) coating and PQWs/3D architecture formation process. A strikingly strong ionic reaction between the 3D perovskite and the long-chain organic cation leads to the quick formation of an ordered intermediate phase within only a few seconds. The optimal PQWs/3D architecture is achieved by controlling the HTAB casting, which is assisted by time-of-flight SIMS characterization. By controlling the second ionic reaction during the long-chain cation coating process, along with the fluorinated poly(triarylamine) (PTAA) as a hole-transport layer, the perovskite solar cells demonstrate efficiencies exceeding 22% along with drastically improved device stability.

Lead halide perovskite materials have recently received considerable attention for achieving an economic and tunable laser owing to their solution-processable feature and promising optical properties. However, most reported perovskite-based lasers operate with a large lasing-mode volume, resulting in a high lasing threshold due to the inefficient coupling between the optical gain medium and cavity. Here, we demonstrate a continuous-wave nanolasing from a single lead halide perovskite (CsPbBr3) quantum dot (PQD) in a plasmonic gap-mode nanocavity with an ultralow threshold of 1.9 Wcm-2 under 120 K. The calculated ultrasmall mode volume (∼0.002 λ3) with a z-polarized dipole and the significantly large Purcell enhancement at the corner of the nanocavity inside the gap dramatically enhance the light-matter interaction in the nanocavity, thus facilitating lasing. The demonstration of PQD nanolasing with an ultralow-threshold provides an approach for realizing on-chip electrically driven lasing and integration into on-chip plasmonic circuitry for ultrafast optical communication and quantum information processing.

Metal halide perovskites having three-dimensional crystal structures are being applied successfully in various optoelectronic applications. To address their most challenging issues—instability and toxicity—without losing efficiency, lower-dimensional perovskites appear to be promising alternatives. Recently, two-dimensional (2D) perovskite solar cells have been developed exhibiting excellent photostability and moisture-stability, together with moderate device efficiency. This review summarizes the photophysical properties and operating mechanisms of 2D perovskites as well as recent advances in their applications in solar cell devices. Also presented is an agenda for the next-stage development of stable perovskite materials for solar cell applications, highlighting the issues of stability and toxicity that require further study to ensure commercialization.

Fully inorganic perovskites based on Bi3+ and Sb3+ are emerging as alternatives that overcome the toxicity and low stability of their Pb-based perovskite counterparts. Nevertheless, thin film fabri...

In this study, we synthesized a series of small-molecule benzotrithiophenes (BTTs) and used them as hole transporting materials (HTMs) in perovskite solar cells (PSCs). The asymmetric benzo[2,1-b:-...

Cost effective imidazole-based star-shaped oligo(arylamines) were easily prepared in good yields via the reaction of one precursor containing two or more aldehydes with a dione compound having two arylamines. High performance perovskite (MAPbI3) solar cells with a conventional cell configuration were fabricated using these compounds as dopant-free hole transport materials. The best solar-to-electricity conversion efficiency reached ∼17.5%, which surpassed that based on LiTFSI/t-BP doped spiro-OMeTAD. The cell also exhibited much better temporal stability than the standard cell of LiTFSI/t-BP doped spiro-OMeTAD, as no hydrophilic dopants are needed.

Dissolution of lithium polysulfide (LiPS) into the electrolyte during discharging, causing shuttling of LiPS from the cathode to the lithium (Li) metal, is mainly responsible for the capacity decay and short battery life of lithium-sulfur batteries (LSBs). Herein, we designed a separator comprising polypropylene (PP) coated with MoO3 nanobelts (MNBs), prepared through facile grinding of commercial MoO3 powder. The formation of Li2Sn-MoO3 during discharging inhibited the polysulfide shuttling; during charging, Li passivated LixMoO3 facilitated ionic transfer during the redox reaction by decreasing the charge transfer resistance. This dual-interaction mechanism of LiPS-with both Mo and the formation of LixMoO3-resulted in a substantially high initial discharge capacity at a very high current density of 5C, with 29.4% of the capacity retained after 5000 cycles. The simple fabrication approach and extraordinary cycle life observed when using this MNB-coated separator suggest a scalable solution for future commercialization of LSBs.

Macrophages and tobacco smoke (TS) exposure have been demonstrated to play significant roles in modulating pulmonary fibrosis (PF). However, the mechanisms of how TS exposure modulates pro-fibrotic macrophage polarization and drives lung fibrosis is unclear. In our study, we investigated how TS modulates macrophage polarization and the functional consequences of this polarization. Multicolor flow cytometric data indicated that markers of M2 macrophage polarization were elevated in both human and mouse macrophage cells and tissues upon TS exposure. In addition, multiple primary lung fibroblast cells demonstrated elevated pro-fibrotic markers and aggressive phenotypes upon interacting with TS-exposed macrophage cells in a co-culture system. Elucidation of the signaling pathways activated by TS exposure through a receptor tyrosine kinase array screen revealed AXL receptor as a novel smoke-responsive molecule in macrophage cells. We noted elevated secretion of AXL ligand, Gas6, and AXL activity in TS exposed cells and tissues. Prior work had demonstrated an interaction between MARCKS, a smoke-responsive protein, and AXL in promoting a pro-fibrotic phenotype in lung fibroblasts. Similarly, we observed AXL activity positively correlated with MARCKS phosphorylation in macrophage cells. Pharmacologic and genetic targeting of the MARCKS/AXL signaling complex reduced M2 markers and profibrotic cytokine production in macrophages and reduced fibrotic changes in the co-culture model and in an animal model of smoke-mediated lung fibrosis. In all, our work suggests that the MARCKS/AXL fibrogenic complex is a potential target in attenuating macrophage activity in TS-mediated fibrosis. Supported by grants from NIH/NHLBI (R01HL146802), DOD DCMRP/PRMRP (PR202411), and UCOP TRDRP (28IR-0061 and T31DT1849).

The three novel acceptor–donor–acceptor (A–D–A) conjugated small molecules were synthesized, each featuring a benzodithiophene (BDT) core presenting lateral flexible side chains: TB-BDT6T substituted with 2-ethynyl-5-octylthiophene, TS-BDT6T substituted with 2-(octylthio)thiophene, and TT-BDT6T substituted with 2-(2-ethylhexyl)thieno[3,2-b]thiophene groups. The lateral incorporation of functionalized π-conjugated flexible side chains, without altering the end-capped acceptor (cyanoacetate) moieties, amended the optoelectronic properties of these BDT-based small molecules. X-ray diffraction spectroscopy revealed that these small molecules possess high crystallinity; moreover, the optimized blend film morphologies, recorded using atomic force microscopy, revealed miscibility with PC61BM, and turn out nanoscale phase separations. The energy levels of the highest occupied and lowest unoccupied molecular orbitals of these small molecules were allowed, leading to high open-circuit voltages (Voc) for their solar...

Controlling circularly polarized (CP) states of light is critical to the development of functional devices for key and emerging applications such as display technology and quantum communication, and the compact circular polarization-tunable photon source is one critical element to realize the applications in the chip-scale integrated system. The atomic layers of transition metal dichalcogenides (TMDCs) exhibit intrinsic CP emissions and are potential chiroptical materials for ultrathin CP photon sources. In this work, we demonstrated CP photon sources of TMDCs with device thicknesses approximately 50 nm. CP photoluminescence from the atomic layers of tungsten diselenide (WSe2) was precisely controlled with chiral metamolecules (MMs), and the optical chirality of WSe2 was enhanced more than 4 times by integrating with the MMs. Both the enhanced and reversed circular dichroisms had been achieved. Through integrations of the novel gain material and plasmonic structure which are both low-dimensional, a compac...

The rapid development of perovskite solar cells (PSCs) has triggered a quest for lead (Pb)-free alternatives to improve their commercial viability. One such non-lead material, the methylammonium antimony iodide zero-dimensional dimer (CH3NH3)3Sb2I9, was reported recently, but with a low photo conversion efficiency (PCE) resulting from its poor surface morphology (many pinholes; amorphous nature). In this study, we employed anti-solvent treatment to improve the surface morphology of the Sb-based dimer by speeding up heterogeneous nucleation. We also incorporated an interlayer that acted as a favorable hydrophobic scaffold for the growth of large-grain (CH3NH3)3Sb2I9 crystals, thereby decreasing the number of the voids and increasing the film quality. We achieved a champion efficiency of 2.77%—a large improvement over the efficiencies reported previously. Using the techniques employed herein to prepare new perovskite-like materials, Sb-based photoabsorbers might become promising replacements for Pb-based perovskites.

In this study, eco-friendly PTCDI-C8–based organic thin film transistors (OTFTs) were fabricated by incorporating polymers from renewable sources as gate dielectrics and substrates. Chitosan, a polysaccharide obtained from the deacetylation of chitin, and natural rubber (NR), extracted from natural rubber tree, have good dielectric properties, biocompatibility, and biodegradability. To examine the practical applicability of these materials, we fabricated OTFTs using bilayer PVPy/NR and chitosan/NR films as gate dielectric materials. NR not only improved the insulation properties of the dielectric film but also acted as a surface modifier. The fabricated OTFT incorporating chitosan/NR dielectric operated under a low driving voltage, with values of μ and Vth of 0.027 cm2V−1s−1 and 0.83 V, respectively. It also displayed an electrical response in the presence of DNA at different concentrations. Because, chitosan possesses high transparency and good mechanical properties, it can be readily cast to form transparent flexible substrates. Accordingly, a flexible disposable OTFT device was fabricated using PVPy/NR as the dielectric material on chitosan as the substrate. The disposable device exhibited a carrier mobility of 0.011 cm2V−1s−1, a value of Vth of 0.83 V, and an on/off ratio of 103, while being workable over 100 bending cycles.

Charge-selective contacts can play a critical role in enhancing the efficiency of perovskite solar cells (PSCs). In this study, we employed fluorine-functionalized graphene (FGr) layers having finely tunable energy levels as hole transport layers (HTLs) to improve the power conversion efficiency (PCE) and stability of inverted PSCs. The non-wetting surface of the FGr enhanced the crystallinity of organic–inorganic perovskites films with large aspect ratios, relative to that of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS). Combining the high work function of the HTL interface with the enhanced crystallinity and limited grain boundary area dramatically decreased the charge recombination losses in organic–inorganic trihalide perovskite (OTP) films. Thus, when incorporating FGr HTLs in inverted PSCs, the best PCE reached 19.34%—the highest efficiency reported to date for any PSC featuring a functionalized graphene HTL. Furthermore, we used this HTL to prepare flexible PSCs and obtained a highest efficiency of 17.50%. Therefore, this highly applicable and facile interface strategy using functionalized graphene HTLs provides stable PSCs displaying high PCEs.

The presence of toxic lead (Pb) remains a major obstruction to the commercial application of perovskite solar cells. Although antimony (Sb)-based perovskite-like structures A3M2X9 can display potentially useful photovoltaic behavior, solution-processed Sb-based perovskite-like structures usually favor the dimer phase, which has poor photovoltaic properties. In this study, we prepared a layered polymorph of Cs3Sb2I9 through solution-processing and studied its photovoltaic properties. The exciton binding energy and exciton lifetime of the layer-form Cs3Sb2I9 were approximately 100 meV and 6 ns, respectively. The photovoltaic properties of the layered polymorph were superior to those of the dimer polymorph. A solar cell incorporating the layer-form Cs3Sb2I9 exhibited an open-circuit voltage of 0.72 V and a power conversion efficiency of 1.5%-the highest reported for an all-inorganic Sb-based perovskite.

Anatase titanium dioxide (an-TiO2) is often used as the electron transporting material (ETM) in planar-heterojunction perovskite solar cells (PSCs) because of its excellent semiconductor characteristics, outstanding optical transmittance, and suitable band structure. Herein, we report an inexpensive method for mass-scale production of TiO2 ETMs at room temperature (RT ∼ 30 °C), involving the grinding of large clumps of an-TiO2 to form a suspension of TiO2 nanoparticles (NPs) in isopropyl alcohol for meso-superstructured PSCs. This process does not involve any chemical synthesis; it is a purely physical process. The lowest unoccupied molecular orbital (LUMO) of ground an-TiO2 NPs, estimated using ultraviolet photoelectron spectroscopy (UPS), was ca. 4.06 eV, which is a salient feature for the active layer. A regular perovskite solar cell (PSC) based on a CH3NH3PbI3 absorber and ground an-TiO2 ETL exhibited a champion power conversion efficiency (PCE) of 17.43% with an active area of 0.1 cm2. The same ground an-TiO2 NPs were used to fabricate a large-area (designated area: 25.2 cm2) PSC and a PCE of 14.19% was achieved. PSC devices incorporating the ground an-TiO2 NP ETLs exhibited an attractive long-term device stability, with the PCE retaining approximately 85% of the initial values after 80 days.

A supramolecular toolbox approach for multivalent ligand-receptor recognition was established based on β-cyclodextrin vesicles (CDVs). A series of bifunctional ligands for CDVs was synthesised. These ligands comprise on one side adamantane, enabling the functionalisation of CDVs with these ligands, and either mannose or sulphate group moieties on the other side for biological receptor recognition. The physicochemical properties of the host-guest complexes formed by β-cyclodextrin (β-CD) and adamantane were determined by isothermal titration calorimetry (ITC). Ligand-lectin interactions were investigated by surface plasmon resonance experiments (SPR) for the mannose ligands and the lectin Concanavalin A (ConA). Microscale thermophoresis (MST) measurements were applied for sulphate-dependent binding to L-selectin. In both cases, a multivalent affinity enhancement became apparent when the ligands were presented on the CDV scaffold. Furthermore, not only the clustering between our supramolecular mannosylated complex and Escherichia coli (E. coli), expressing the lectin FimH, was visualised by cryo-TEM, but also the competitive character to detach bound E. coli from a cell line, representing the uroepithelial cell surface, was demonstrated. In summary, a facile and effective supramolecular toolbox was established for various ligand-receptor recognition applications.

In this work, self-assembled monolayers of a series of para-substituted phenylphosphonic acids were formed on the ITO substrate surface for the fabrication of perovskite-based solar cells. With the perovskite layer directly transferred by a stamping method on the SAM-modified ITO surface, followed by spin-coated PCBM layer, an inverted-type, hole-transport layer-free solar cell was fabricated. The device characteristics, such as open circuit voltage Voc, short circuit current Jsc, and field factor FF, were analyzed with respect to the energy level alignment at the ITO/perovskite interface. The best power conversion efficiency was observed with ITO having work function closest to the valence band maximum of perovskite, giving an efficiency of 13.94 %, considerably higher than the 8.64 % from the bare ITO-based device.

A facile solution process was employed to prepare CsPbI3 as an anode material for Li-ion batteries. Rietveld refinement of the X-ray data confirms the orthorhombic phase of CsPbI3 at room temperature. As obtained from bond valence calculations, strained bonds between Pb and I are identified within PbI6 octahedral units. Morphological study shows that the as-prepared δ-CsPbI3 forms a nanorod-like structure. The XPS analysis confirm the presence of Cs (3d, 4d), Pb (4d, 4f, 5d) and I (3p, 3d, 4d). The lithiation process involves both intercalation and conversion reactions, as confirmed by cyclic voltammetry (CV) and first-principles calculations. Impedance spectroscopy coupled with the distribution function of relaxation times identifies charge transfer processes due to Li metal foil and anode/electrolyte interfaces. An initial discharge capacity of 151 mAhg−1 is found to continuously increase to reach a maximum of ~275 mAhg−1 at 65 cycles, while it drops to ~240 mAhg−1 at 75 cycles and then slowly decreases to 235 mAhg−1 at 100 cycles. Considering the performance and structural integrity during electrochemical performance, δ-CsPbI3 is a promising material for future Li-ion battery (LIB) application.

The search for stable alternative lead-free perovskites has identified all-inorganic antimony/bismuth halide derivatives as promising materials. Despite attractive optoelectronic properties, their wider band gaps and poor morphological control have greatly limited their solar device performance. In this study, we used the indacenodithiophene-based organic acceptor (ITIC) as a Lewis base to improve the morphology of Cs3Sb2I9 films and also as an electron transport layer to form a complimentary heterojunction, and, thereby, enhance the performance of Cs3Sb2I9 solar cells. The presence of cyano and carbonyl groups in ITIC modulated the rate of crystallization of Cs3Sb2I9 and improved its optoelectronic properties. The panchromatic absorption of the Cs3Sb2I9/ITIC heterostructure provided a power conversion efficiency of 3.25% in inverted solar cell structure under 1-sun irradiation. This enhanced performance when using a complimentary absorption strategy suggests a new pathway for developing wider-band-gap lead-free perovskite derivatives for solar cell applications. Moreover, the optimized Cs3Sb2I9/ITIC heterostructure–based solar cell achieved a PCE of 9.2% under indoor illumination at 1000 lx, highlighting the potential use of such devices in indoor applications.

A highly efficient electron transport layer (ETL) is an essential constituent for good performance and stability in planar perovskite solar cells. Among n-type metal oxide materials, zinc oxide (ZnO) is a promising candidate for an electron transport layer due to its relatively high electron mobility, high transparency, and versatile nanostructures. However, it was found that several disadvantages could occur at the ZnO/perovskite interface, such as decomposition of CH3NH3PbI3 and poorly aligned energy levels. To overcome these issues, we present a design based on staircase band alignment of a low-temperature solution-processed ZnO/Al-doped ZnO (AZO) bilayer thin film as electron transport layers in planar perovskite solar cells. Experimental results revealed that the power conversion efficiency (PCE) of perovskite solar cells was significantly increased from 12.3% to 16.1% by employing the AZO thin film as the buffer layer. Meanwhile, the short-circuit current density (Jsc), open-circuit voltage (Voc), a...

In this paper we describe a modified (AEG/CH) coated separator for Li-S batteries in which the shuttling phenomenon of the lithium polysulfides is restrained through two types of interactions: activated expanded graphite (AEG) flakes interacted physically with the lithium polysulfides, while chitosan (CH), used to bind the AEG flakes on the separator, interacted chemically through its abundance of amino and hydroxyl functional groups. Moreover, the AEG flakes facilitated ionic and electronic transfer during the redox reaction. Live H-cell discharging experiments revealed that the modified separator was effective at curbing polysulfide shuttling; moreover, X-ray photoelectron spectroscopy analysis of the cycled separator confirmed the presence of lithium polysulfides in the AEG/CH matrix. Using this dual functional interaction approach, the lifetime of the pure sulfur-based cathode was extended to 3000 cycles at 1C-rate (1C = 1670 mA/g), decreasing the decay rate to 0.021% per cycle, a value that is among the best reported to date. A flexible battery based on this modified separator exhibited stable performance and could turn on multiple light-emitting diodes. Such modified membranes with good mechanical strength, high electronic conductivity, and anti-self-discharging shield appear to be a scalable solution for future high-energy battery systems.

In this study, we observed a decrease in interfacial recombination within organic/inorganic hybrid solar cells when using NbSex interfacial layer between the buffer layer and the active layer. The NbSex layer effectively decreased the built-in potential between PEDOT:PSS and BiI3, allowing effective transport of holes from the active layer to the hole transporting layer, due to its good conductivity (metallic behavior and high work function). In addition, the NbSex layer decreased the recombination of charge carriers at the interfaces and allowed the electron/hole pairs to separate efficiently. Such interfacial modification led to the formation of a uniform surface and, thereby, to an improved BiI3 morphology. Simultaneous enhancements of the short-circuit current density and open-circuit voltage resulted in the optimal power conversion efficiency increasing from 0.33 to 0.64% after incorporating a thin NbSex interfacial layer. Therefore, the NbSex interfacial layer appears to play a dual role in BiI3 solar cells: enhancing the optical properties while minimizing recombination.

Inorganic–organic hybrid perovskite solar cells (PSCs) are promising devices for providing future clean energy because of their low cost, ease of fabrication, and high efficiencies, similar to those of silicon solar cells. These materials have been investigated for their potential use in bifacial PSCs, which can absorb light from both sides of the electrodes. Here, we fabricated bifacial PSCs featuring transparent BCP/Ag/MoO3 rear electrodes, which we formed through low-temperature processing using thermal evaporation methods. We employed a comprehensive optical distribution program to calculate the distributions of the optical field intensities with constant thicknesses of the absorbing layer in the top electrode configuration. The best PSC having a transparent BCP/Ag/MoO3 electrode achieved PCEs of 13.49% and 9.61% when illuminated from the sides of the indium tin oxide and BCP/Ag/MoO3 electrodes, respectively. We observed significant power enhancement when operating this PSC using mirror reflectors and...

Pristine MoO3 is a potential anode material for lithium-ion batteries (LIBs), due to its high specific capacity (1117 mA h g−1); it suffers, however, from poor cyclability, resulting from a low conductivity and large volume changes during lithiation/delithiation process. Here we adopt a facile two-step method in which pristine bulk MoO3 is first converted into MoO3 nanorods (MoO3 NR) through mechanical grinding, to buffer the continuous volume changes, and then coated with amorphous carbon through simple stirring and heating, to provide high electronic and ionic conductivities. Electrochemical tests reveal that the carbon-coated MoO3 nanorods (C-MoO3 NRs) exhibit outstanding specific capacity (856 mA h g−1 after 110 cycles at a current density of 0.1 C); remarkable cycle life, among the best reported for carbon-based MoO3 nanostructures (485 mA h g−1 after 300 cycles at 0.5 C and 373 mA h g−1 after 400 cycles at 0.75 C); and greatly improved capacity retention (up to 90.4% after various C-rates) compared to bulk MoO3. We confirm the versatility of the C-MoO3 NR anodes by preparing flexible batteries that display stable performance, even in bent state. This simple approach toward C-MoO3 NR anodes proceeds without rigorous chemical synthesis or extremely high temperatures, making it a scalable solution to prepare high-capacity anodes for next-generation LIBs.

A series of donor–acceptor (D–A) polymers (P1–P3) based on benzodithiophene (BDT) and electron-accepting benzotriazole (BTZ) units containing thiophene linkers with/without alkyl side-chains were designed and synthesized via Stille coupling polymerization method. The effects of polymers with multiple fluorinated BTZ groups on their thermal, optical, electrochemical, and photovoltaic properties were investigated. These polymers possessed the highest occupied molecular orbital (HOMO) levels ranged −5.38 to −5.6 eV and the lowest unoccupied molecular orbital (LUMO) levels ranged −3.55 to −3.57 eV, which covered broad absorption ranges with low optical bandgaps. The bulk heterojunction (BHJ) polymer solar cell (PSC) devices containing an active layer of D-A polymers blended with different weight ratios of electron-acceptor [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) were explored under 100 mW cm−2 of AM 1.5 white-light illumination, where the maximum power conversion efficiency (PCE) value of 3% (with Jsc = 7.70 mA/cm2, FF = 54.04, and Voc = 0.72 V) was obtained in the PSC device consisting of polymer P3.

This study represents an important discovery that employs donor–acceptor (D–A) energy transfer-based strategies to construct water-soluble hybrid micelles with hydrophilic sodium ion-functionalized polythiophene (PTA-Na) as a donor and hydrophobic fullerene (C60) as an acceptor, enabling the production of multifunctional self-assembled micelles for applications in environmentally friendly electronic devices. The C60-loaded micelles exhibit uniform nanospherical shape and morphology, tunable C60 loading capacity and excellent C60-entrapment stability, in combination with unique electrochemical properties due to highly efficient D–A energy transfer from PTA-Na to C60. In addition, spin-coated PTA-Na/C60 film possessed superior electrical conductivity of up to 1.85 × 10−1 S cm−1, nearly one order of magnitude higher than that of pristine PTA-Na film under the same experimental conditions. More importantly, when PTA-Na/C60 micelles were employed as the conducting layer in an aqueous-processed single-layer conductive device, the resulting device exhibited substantially higher electrical performance than control PTA-Na and C60 devices. Given its simplicity of fabrication, multifunctional properties, high efficiency and environmentally friendly characteristics, this newly-developed water-soluble heterojunction material provides a new route to enable the development of high-performance aqueous-processed electronic devices.

Nucleobase-functionalized conjugated polymers (NCPs) utilize molecular self-assembly to spontaneously arrange into three-dimensional supramolecular polymer networks through complementary multiple hydrogen bonding interactions. NCPs behave as a highly efficient optoelectronic material with substantially enhanced overall physical properties, making them highly attractive for a wide range of optical and electronic applications. Due to the ease of varying the extent of the reversible network by tuning the complementary base pairing content, these newly-developed NCPs could be easily tailored to meet specific requirements with respect to thermal stability, optical properties and energy band gaps for the fabrication of organic light emitting diode (OLED) devices. When NCPs were employed as the hole injection layer (HIL) in a solution-processed three-layer OLED device, a low turn-on voltage (2.9 V), maximum brightness as high as ∼52 000 cd m−2 and a luminous efficiency of 9.7 cd A−1 were achieved; these values were much higher than those of control samples and conventional HIL-based devices. Thus, this new system provides a new direction to further improve the hole-injection ability of conjugated polymers and hence offers opportunities towards the design and development of high-performance multilayer OLED devices.

Organic–inorganic lead halide perovskites have recently emerged as highly competitive light absorbing materials for low cost solution-processable photovoltaic devices. With the high efficiency already achieved, removing the toxicity, i.e., lead-free and stability are the key obstacles for perovskite solar cells. Here, we report the synthesis of an antimony (Sb)-based hybrid material having the composition of A3Sb2I9 [A = CH3NH3 (MA), Cs] and an investigation of its potential photovoltaic applications. Sb-based perovskite-like materials exhibited attractive absorbance properties, with the band gaps of MA3Sb2I9 and Cs3Sb2I9 measured to be 1.95 and 2.0 eV, respectively. X-ray photoelectron spectroscopy confirmed the formation of stoichiometric perovskites from appropriate precursor molar ratios incorporated with hydroiodic acid (HI). Planar hybrid Sb-based solar cells exhibited negligible hysteresis and reproducible power output under working conditions. A power conversion efficiency of 2.04% was achieved by the MA3Sb2I9 perovskite-based device—the highest reported to date for a Sb-based perovskite solar cell.

Temperature is a characteristic often correlated with environmental and health issues. This paper presents an organic thin film transistor (OTFT) based temperature sensor having a detection range of 30–45 °C, which, therefore, encompasses the human body temperature. The OTFT sensor featured thermosensitive poly(N-isopropylacrylamide) (PNIPAM) and pentacene as the gate dielectric and semiconductor, respectively. The PNIPAM film possessed a dielectric constant of 4.2 with very low leakage current density. The OTFT exhibited high electrical performance, with a hole mobility (μ) of 0.90 ± 0.04 cm2 V−1 s−1, a threshold voltage (Vth) of −15.4 ± 1.16 V, and an on/off ratio of 104. Significant changes in the drain current and the values of Vth and μ occurred when the temperature of the device was varied within the range 30–45 °C at an interval of 0.5 °C. The operating principle for this temperature sensor was based on the structural transformation of the PNIPAM dielectric and the enhanced charge transport of the pentacene semiconductor upon varying the temperature. Flexible OTFTs fabricated on polyethylene terephthalate substrate displayed hole mobilities as high as 0.39 ± 0.01 cm2 V−1 s−1, values of Vth of −18.6 ± 0.45, and on/off ratios of 102, and were workable for over 100 bending cycles.

High energy density battery technology for portable electronics and grid energy system are in high demand. Lithium anode considered as the suitable electrode for commercialization of lithium-ion battery because of having highest specific capacity, lowest reduction potential and low density. However, uncontrolled lithium dendrite growth results in low coulombic efficiency, internal short-circuit of the cells. Here, we demonstrate δ-CsPbI3 as a protective layer for lithium metal anode fabricated by a low-cost, facile spray coating methodology. Furthermore, experimental and density function theory study confirms the lithium ion intercalate in the crystal structure of δ-CsPbI3. Lithium intercalation into δ-CsPbI3 fast the lithium ion migration, stabilize the electrodeposition and maintain the integrity of SEI layer. We observe a dendrite free plating for 1000 hours at a current density of 1 mA cm-2 and discharge capacity of 1 mAh cm-2. We achieve a starting discharge capacity of 823 mAh g-1 and coulombic efficiency of ⁓100% throughout 1000 cycles with decay rate of ⁓0.035% per cycle in a Li-Sulfur full cell configuration. Our new concept accomplish a stable lithium metal for future commercialization and open up new area of research to achieve safe lithium anode.

Dissolution of lithium polysulfide (LiPS) into the electrolyte during discharging, causing shuttling of LiPS from the cathode to the lithium (Li) metal, is mainly responsible for the capacity decay and short battery life of lithium-sulfur batteries (LSBs). Herein, we designed a separator comprising polypropylene (PP) coated with MoO3 nanobelts (MNBs), prepared through facile grinding of commercial MoO3 powder. The formation of Li2Sn-MoO3 during discharging inhibited the polysulfide shuttling; during charging, Li passivated LixMoO3 facilitated ionic transfer during the redox reaction by decreasing the charge transfer resistance. This dual-interaction mechanism of LiPS-with both Mo and the formation of LixMoO3-resulted in a substantially high initial discharge capacity at a very high current density of 5C, with 29.4% of the capacity retained after 5000 cycles. The simple fabrication approach and extraordinary cycle life observed when using this MNB-coated separator suggest a scalable solution for future commercialization of LSBs.

Despite issues related to dendrite formation, research on Li metal anodes has resurged because of their high energy density. In this study, graphene oxide (GO) layers are decorated onto Li metal anodes through a simple process of drop-casting and spray-coating. The self-assembly of GO is exploited to synthesize coatings having compact, mesoporous, and macroporous morphologies. The abilities of the GO coatings to suppress dendrite formation are compared through Li|Li symmetrical cell charging at a current density of 5 mA cm–2 for 2000 cycles—a particularly abusive test. The macroporous structure possesses the lowest impedance, whereas the compact structure excels in terms of stability. Moreover, GO exhibits a low nucleation overpotential and is transformed into reduced GO with enhanced conductivity during the operation of the cells; both factors synergistically mitigate the issue of dendrite formation. Li–S batteries incorporating the GO-decorated Li anodes exhibit an initial capacity of 850 mA h g–1 and m...

Three azahelicene derivatives with electron-rich bis(4-methoxyphenyl)amino or bis( p-methoxyphenyl)aminophenyl groups at the terminals were deliberately designed, synthesized, and characterized as hole-transporting materials (HTMs) for perovskite solar cells (PSCs). Optical and thermal properties, energy level alignments, film morphologies, hole extraction ability, and hole mobility were studied in detail. PSCs using the newly synthesized molecules as HTMs were fabricated. A maximum power conversion efficiency (PCE) of 17.34% was observed for the bis( p-methoxyphenyl)amino-substituted derivative (SY1) and 16.10% for the bis( p-methoxyphenyl)aminophenyl-substituted derivative (SY2). Longer-chain substituent such as hexyloxy group greatly diminishes the efficiency. In addition, the dopant-free devices fabricated with SY1 as the HTM shows an average PCE of 12.13%, which is significantly higher than that of spiro-OMeTAD (7.61%). The ambient long-term stability test revealed that after 500 h, the devices prepared from SY1 and SY2 retained more than 96% of its initial performance, which is much improved than the reference device with standard spiro-OMeTAD as the HTM under the same conditions. Detailed material cost analysis reveals that the material cost for SY1 is less than 8% of that for spiro-OMeTAD. These results provide a useful direction for designing a new class of HTMs to prepare highly efficient and more durable PSCs.

Metal oxide transporting layer in organic-inorganic perovskite solar cells (PSCs) have a tremendous improvement in both aspects, first stability and second high power conversion efficiency (PCE) which provides a new platform for commercialization in near future. Herein we report for the first time a novel home-made ball milling technique for the synthesis of tin oxide (SnO2) nanoparticles (10~20 nm sizes) fabricated at composite temperature, employed as an electron transporting layer (ETL) in planar PSCs. A smartly designed ground SnO2 (G-SnO2) NPs which annealed at high temperature (≤ 300°C) and an additional layer of a SnO2 layer (C-SnO2) which converted from the precursor (SnCl2.2H2O), annealed at low temperature (≤ 200°C). This synergistic effect gives a pinhole-free layer of G-SnO2 NPs, which helps to improve the bonding and interlayer recombination between ETL and absorber layer. We fabricated C-SnO2, G-SnO2, and G-SnO2/C-SnO2 based PSCs, with champion PCE of 16.4%, 17.9% and 19.11% respectively, with an active area of 0.04 cm2. The G-SnO2 and G-SnO2/C-SnO2 based devices have long-term stability and less hysteresis compare to C-SnO2 based device.

This manuscript describes how to design and fabricate efficient inverted solar cells, which are based on a two-dimensional conjugated small molecule (SMPV1) and [6,6]-phenyl-C71-butyric acid methyl ester (PC(71)BM), by utilizing ZnO nanorods (NRs) grown on a high quality Al-doped ZnO (AZO) seed layer. The inverted SMPV1:PC(71)BM solar cells with ZnO NRs that grew on both a sputtered and sol-gel processed AZO seed layer are fabricated. Compared with the AZO thin film prepared by the sol-gel method, the sputtered AZO thin film exhibits better crystallization and lower surface roughness, according to X-ray diffraction (XRD) and atomic force microscope (AFM) measurements. The orientation of the ZnO NRs grown on a sputtered AZO seed layer shows better vertical alignment, which is beneficial for the deposition of the subsequent active layer, forming better surface morphologies. Generally, the surface morphology of the active layer mainly dominates the fill factor (FF) of the devices. Consequently, the well-aligned ZnO NRs can be used to improve the carrier collection of the active layer and to increase the FF of the solar cells. Moreover, as an anti-reflection structure, it can also be utilized to enhance the light harvesting of the absorption layer, with the power conversion efficiency (PCE) of solar cells reaching 6.01%, higher than the sol-gel based solar cells with an efficiency of 4.74%.

Further technological development of perovskite solar cells (PSCs) will require improvements in power conversion efficiency and stability, while maintaining low material costs and simple fabrication. In this Research Article, we describe top-illuminated ITO-free, stable PSCs featuring microcavity structures, wherein metal layers on both sides on the active layers exerted light interference effects in the active layer, potentially increasing the light path length inside the active layer. The optical constants (refractive index and extinction coefficient) of each layer in the PSC devices were measured, while the optical field intensity distribution was simulated using the transfer matrix method. The photocurrent densities of perovskite layers of various thicknesses were also simulated; these results mimic our experimental values exceptionally well. To modify the cavity electrode surface, we deposited a few nanometers of ultrathin MoO3 (2, 4, and 6 nm) in between the Ag and poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) layers provide hydrophobicity to the Ag surface and elevate the work function of Ag to match that of the hole transport layer. We achieved a power conversion efficiency (PCE) of 13.54% without hysteresis in the device containing a 4 nm-thick layer of MoO3. In addition, we fabricated these devices on various cavity electrodes (Al, Ag, Au, Cu); those prepared using Cu and Au anodes displayed improved device stability of up to 72 days. Furthermore, we prepared flexible PSCs having a PCE of 12.81% after incorporating the microcavity structures onto poly(ethylene terephthalate) as the substrate. These flexible solar cells displayed excellent stability against bending deformation, maintaining greater than 94% stability after 1000 bending cycles and greater than 85% after 2500 bending cycles performed with a bending radius of 5 mm.

A new and novel organic–inorganic light-emitting material (POSS–DPCz) behaves as an effective chromophore and offers substantially improved fluorescence-color purity and quantum yield compared to control DPCz without incorporated POSS. When POSS–DPCz was utilized as an emissive layer in a solution-processed three-layer OLED device, the performance of the resulting device is almost two times higher than that of the control DPCz-based device.