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Graphical Abstract: Schematic showing that the Seebeck coefficient of PDPP-4T changes sign from positive to negative upon heavy doping with the small BF4−counterion, but no sign change is observed with the larger BArF−counterion

Transparent conductors (TCs) play a vital role in displays, solar cells, and emerging printed electronics. Here, we report a solution-processable n-doped organic conductor from copper-catalyzed cascade reactions in the air, which involves oxidative polymerization and reductive doping in one pot. The formed polymer ink is shelf-stable over 20 days and can endure storage temperatures from −20 to 65 °C. The optimized n-doped thin-film TC exhibits a low sheet resistance of 45 Ω/sq and a high transmittance (T550> 80%), which can rival indium tin oxide. The transparent organic conductor exhibits excellent durability under accelerated weathering tests (85 °C/85% RH). Furthermore, the n-doped polymer film can also function as an electrode material with a high volumetric capacity. When it is paired with p-doped PEDOT:PSS, a record-high coloration efficiency is obtained in a dual-polymer electrochromic device.

Inverted perovskite solar cells (PSCs) promise enhanced operating stability compared to their normal-structure counterparts1–3. To improve efficiency further, it is crucial to combine effective light management with low interfacial losses4,5. Here we develop a conformal self-assembled monolayer (SAM) as the hole-selective contact on light-managing textured substrates. Molecular dynamics simulations indicate that cluster formation during phosphonic acid adsorption leads to incomplete SAM coverage. We devise a co-adsorbent strategy that disassembles high-order clusters, thus homogenizing the distribution of phosphonic acid molecules, and thereby minimizing interfacial recombination and improving electronic structures. We report a laboratory-measured power conversion efficiency (PCE) of 25.3% and a certified quasi-steady-state PCE of 24.8% for inverted PSCs, with a photocurrent approaching 95% of the Shockley–Queisser maximum. An encapsulated device having a PCE of 24.6% at room temperature retains 95% of its peak performance when stressed at 65 °C and 50% relative humidity following more than 1,000 h of maximum power point tracking under 1 sun illumination. This represents one of the most stable PSCs subjected to accelerated ageing: achieved with a PCE surpassing 24%. The engineering of phosphonic acid adsorption on textured substrates offers a promising avenue for efficient and stable PSCs. It is also anticipated to benefit other optoelectronic devices that require light management.

All-perovskite tandem solar cells hold the promise of surpassing the efficiency limits of single-junction solar cells1–3; however, until now, the best-performing all-perovskite tandem solar cells have exhibited lower certified efficiency than have single-junction perovskite solar cells4,5. A thick mixed Pb–Sn narrow-bandgap subcell is needed to achieve high photocurrent density in tandem solar cells6, yet this is challenging owing to the short carrier diffusion length within Pb–Sn perovskites. Here we develop ammonium-cation-passivated Pb–Sn perovskites with long diffusion lengths, enabling subcells that have an absorber thickness of approximately 1.2 μm. Molecular dynamics simulations indicate that widely used phenethylammonium cations are only partially adsorbed on the surface defective sites at perovskite crystallization temperatures. The passivator adsorption is predicted to be enhanced using 4-trifluoromethyl-phenylammonium (CF3-PA), which exhibits a stronger perovskite surface-passivator interaction than does phenethylammonium. By adding a small amount of CF3-PA into the precursor solution, we increase the carrier diffusion length within Pb–Sn perovskites twofold, to over 5 μm, and increase the efficiency of Pb–Sn perovskite solar cells to over 22%. We report a certified efficiency of 26.4% in all-perovskite tandem solar cells, which exceeds that of the best-performing single-junction perovskite solar cells. Encapsulated tandem devices retain more than 90% of their initial performance after 600 h of operation at the maximum power point under 1 Sun illumination in ambient conditions.

The energy landscape of reduced-dimensional perovskites (RDPs) can be tailored by adjusting their layer width (n). Recently, two/three-dimensional (2D/3D) heterostructures containing n= 1 and 2 RDPs have produced perovskite solar cells (PSCs) with >25% power conversion efficiency (PCE). Unfortunately, this method does not translate to inverted PSCs due to electron blocking at the 2D/3D interface. Here we report a method to increase the layer width of RDPs in 2D/3D heterostructures to address this problem. We discover that bulkier organics form 2D heterostructures more slowly, resulting in wider RDPs; and that small modifications to ligand design induce preferential growth of n≥ 3 RDPs. Leveraging these insights, we developed efficient inverted PSCs (with a certified quasi-steady-state PCE of 23.91%). Unencapsulated devices operate at room temperature and around 50% relative humidity for over 1,000 h without loss of PCE; and, when subjected to ISOS-L3 accelerated ageing, encapsulated devices retain 92% of initial PCE after 500 h.

Chemical and electrochemical doping of π‐conjugated polymers is an important aspect in determining the performance and enabling the operation of many organic electronic devices, from organic light emitting diodes and thermoelectrics to organic electrochemical transistors. In both chemical doping and electrochemical doping an ionized dopant or counterion is present along with the doped π‐conjugated polymer. This dopant or counterion is not a benign spectator, rather, its presence can significantly impact the optical, electronic, and thermoelectric properties of the resulting material. Here, we investigate how counterion structure impacts the electrochemical doping ability, oxidation potential, ionization energy, and polaron absorbance of regioregular (rr) and regiorandom (rra) P3HT. We find that in most cases the anion has a small effect on the polymer oxidation potential, except for in the case of rr‐P3HT with the large tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate anion. We propose that this large anion is excluded from the crystalline regions and thus the oxidation potential is similar to that of rra‐P3HT. The anions also result in significant differences in polaron absorbance and ionization energies, thereby emphasizing the important role of the counterion in determining the optical and electronic properties of doped π‐conjugated polymers.

It is commonly assumed that charge-carrier transport in doped π-conjugated polymers is dominated by one type of charge carrier, either holes or electrons, as determined by the chemistry of the dopant. Here, through Seebeck coefficient and Hall effect measurements, we show that mobile electrons contribute substantially to charge-carrier transport in π-conjugated polymers that are heavily p-doped with strong electron acceptors. Specifically, the Seebeck coefficient of several p-doped polymers changes sign from positive to negative as the concentration of the oxidizing agents FeCl3or NOBF4increase, and Hall effect measurements for the same p-doped polymers reveal that electrons become the dominant delocalized charge carriers. Ultraviolet and inverse photoelectron spectroscopy measurements show that doping with oxidizing agents results in elimination of the transport gap at high doping concentrations. This approach of heavy p-type doping is demonstrated to provide a promising route to high-performance n-type organic thermoelectric materials.

ABSTRACTPrior research on marketing curriculum design suggests that new course offerings are driven by inputs from faculty resources and interests, student demand and willingness to enroll in the course, and feedback from alumni and employers regarding the skills students need to be successful in the workplace. In the face of the rising costs of higher education and declining enrollments, it is critical that curriculum be developed that strikes a balance between the values and needs of faculty, students, and employers. The current study explores the disconnect between courses students most desire to take and courses business professionals most recommend they take for career success. Utilizing Expectancy-Value Theory (EVT) and the Theory of Consumption Values (TCV) as lenses to explore student choice in regard to marketing elective course selection, this study offers empirical data on courses preferred by marketing students and recommended by employers. Findings elucidate similarities and differences between these two stakeholders, which faculty making curriculum decisions will need to navigate. Implications for theory and practice are discussed, including recommendations for curriculum design and strategies for balancing the preferences of students with the recommendations and demands of potential employers.

Two-dimensional metal halide perovskite nanocrystals are attractive for their blue-shifted absorption relative to their 3D counterparts, narrow emission line widths, high absorption cross sections, and high radiative recombination. Herein, we report a ligand mediated anion exchange reaction that transforms CsPbCl3nanocubes into anisotropic CsPbX3nanoplates (NPs) through adding a mixture of dodecanethiol (DDT) and AlX3(X = Cl, Br, I) to a solution of CsPbCl3nanocrystals. The anion-exchanged nanocrystals consist of mostly plate-shaped CsPbX3nanocrystals along {010} facets. Although DDT or AlX3treatment alone results in increased photoluminescence quantum yield, ΦPL, the combination of both DDT and AlX3leads to the formation of plate-shaped nanocrystals, higher ΦPL, and improved stability as compared to when only one of these is used. We suspect nanocrystal exfoliation driven by ligand penetration and self-assembly both play important roles in transforming the parent nanocubes into NPs. The NPs are highly emissive and stable due to the introduction of both an anion source and surface ligand. Nanoplates synthesized through DDT-AlX3ligand mediated anion exchange show photoluminescence quantum yields of 47 and 65% for violet and blue emitters (CsPbCl3and CsPbCl3–xBrx), respectively, near 100% for green emitters (CsPbBr3), and 81% for red emitters (CsPbI3), while maintaining good long-term stability.

Purpose: The purpose of this paper is to use social identity theory and the elaboration likelihood model to explore differences in consumer response to positive and negative online brand advertising based on the degree to which the consumer identifies with the brand featured in the ad. Dependent variables include attitude toward the ad, attitude toward the brand, willingness to share the ad and purchase intention. Design/methodology/approach: This study uses a posttest-only, 2 (low consumer–brand identification v. high consumer–brand identification) × 2 (negative advertisement v. positive advertisement) between-subjects factorial design for two separate brands based on the pretest results. Findings: Results show, in support of extant research, that consumer–brand identification enhances consumer perceptions of positive brand advertising. In addition, this research shows that consumer–brand identification also minimizes the potentially detrimental effects of negative advertisements on the dependent variables. Further, results suggest that those with a low consumer–brand identification are more likely to share negative online brand advertising. Practical implications: Building consumer–brand identification among target consumers results in positive brand attitudes and behaviors while at the same time shielding brands from negative online attack advertising. However, consumers with weak consumer–brand identification can be influenced through peripheral cues in online ads. This research indicates that managers need to focus on strengthening consumer–brand identity with target audiences and closely monitor negative online sentiment. Originality/value: This exploratory research extends current consumer–brand relationship scholarship and adds support for application of the elaboration likelihood model in an online environment. To the best of the authors’ knowledge, this study is the first to examine the role of consumer–brand identity and its role in explaining consumer responses to online display advertising.

Interfacial chemistry and energetics significantly impact the performance of photovoltaic devices. In the case of Pb-containing organic metal halide perovskites, photoelectron spectroscopy has been used to determine the energetic alignment of frontier electronic energy levels at various interfaces present in the photovoltaic device. For the Sn-containing analogues, which are less toxic, no such measurements have been made. Through a combination of ultraviolet, inverse, and X-ray photoelectron spectroscopy (UPS, IPES, and XPS, respectively) measurements taken at varying thickness increments during stepwise deposition of C60on FASnI3, we present the first direct measurements of the frontier electronic energy levels across the FASnI3/C60interface. The results show band bending in both materials and transport gap widening in FASnI3at the interface with C60. The XPS results show that iodide diffuses into C60and results in n-doping of C60. This iodide diffusion out of FASnI3impacts the valence and conduction band energies of FASnI3more than the core levels, with the core level shifts displaying a different trend than the valence and conduction bands. Surface treatment of FASnI3with carboxylic acids and bulky ammonium substituted surface ligands results in slight alterations in the interfacial energetics, and all surface ligands result in similar or improved PV performance relative to the untreated devices. The greatest PV stability results from treatment with a fluorinated carboxylic acid derivative; however, iodide diffusion is still observed to occur with this surface ligand.

Precise doping of organic semiconductors allows control over the conductivity of these materials, an essential parameter in electronic applications. Although Lewis acids have recently shown promise as dopants for solution-processed polymers, their doping mechanism is not yet fully understood. In this study, we found that B(C6F5)3is a superior dopant to the other Lewis acids investigated (BF3, BBr3and AlCl3). Experiments indicate that Lewis acid–base adduct formation with polymers inhibits the doping process. Electron–nuclear double-resonance and nuclear magnetic resonance experiments, together with density functional theory, show that p-type doping occurs by generation of a water–Lewis acid complex with substantial Brønsted acidity, followed by protonation of the polymer backbone and electron transfer from a neutral chain segment to a positively charged, protonated one. This study provides insight into a potential path for protonic acid doping and shows how trace levels of water can transform Lewis acids into powerful Brønsted acids.

Two-dimensional halide perovskites (2D-HPs) are of significant interest for their applications in optoelectronic devices. Part of this increased interest in 2D-HPs stems from their increased stability relative to their three-dimensional (3D) counterparts. Here, the origin of higher stability in 2D-HPs is mainly attributed to the bulky ammonium cation layers, which can act as a blocking layer against moisture and oxygen ingression and ion diffusion. While 2D-HPs have demonstrated increased stability, it is not clear how the structure of the ammonium ions impacts material stability. Herein, we investigate how the structure of ammonium cations, including three n-alkyl ammoniums, phenethylammonium (PEA) and five PEA derivatives, anilinium (An), benzylammonium (BzA), and cyclohexylmethylammonium (CHMA), affects the crystal structure and air, water, and oxygen stability of 2D tin halide perovskites (2D-SnHPs). We find that stability is influenced by several factors, including the molecular packing and intermolecular interactions in the organic layer, steric effects around the ammonium group, the orientation distribution of the 2D sheets, and the hydrophobicity of the perovskite film surface. With superior hydrophobicity, strong interactions between organic molecules, and a high extent of parallel oriented inorganic sheets, the 2-(4-trifluoromethyl-phenyl)-ethylammonium (4-TFMPEA) ion forms the most stable 2D-SnHP among the 12 ammonium cations investigated.

The concept of complementary semiconducting polymer blends (c-SPBs) has been recently proposed to achieve enhanced solution processability and/or melt-processing capability for organic electronics. In the previous study, we demonstrated the impact of conjugation-break spacers of matrix polymers. In the current work, we explore the influence of the side chains of the matrix polymer on the physical properties of the pure polymers and their corresponding c-SPBs, including electrical properties and phase transition behaviors. Six diketopyrrolopyrrole (DPP)-based polymers with pentamethylene conjugation-break spacers (CBSs) and various side chains, including branched-alkyl, triethylene glycol (TEG), and siloxane-terminated side chains, were synthesized and characterized. The UV–vis spectra show that the side chains have a noticeable impact on the intermolecular interactions in the solid states. In addition, side chains also have a significant influence on the thermal behaviors of the polymers. Polymers with asymmetric side chains attached to the same DPP unit exhibit lower melting points compared to the congeners with symmetric side chains. The polymer with both branched-alkyl and TEG side chain exhibits the lowest melting point of 104 °C. As for charge transport properties, polymers with branched-alkyl and/or siloxane-terminated side chains give hole mobilities on the same order of magnitude, whereas the polymers with TEG side chains exhibits much lower mobilities. When c-SPBs with a fully conjugated polymer with branched-alkyl side chains are concerned, the c-SPBs of all polymers, except for the polymer with only TEG side chains (TEG-DPP-C5), show hole mobilities 2 orders of magnitude higher than the corresponding pure matrix polymers. In contrast, TEG-DPP-C5 merely presents an improvement of 20 times, which resulted from the incompatibility of TEG side chains from the matrix polymer and the alkyl side chains from the tie chain polymer. These results provide new insights into structural design for semiconducting materials with both high performance and better processability.

Halogenation, particularly fluorination, is commonly used to manipulate the energetics, stability, and morphology of organic semiconductors. In the case of organic photovoltaics (OPVs), fluorination of electron donor molecules or polymers at appropriate positions can lead to improved performance. In this contribution, we use ultraviolet photoelectron spectroscopy, external quantum efficiency measurements of charge-transfer (CT) states, and density functional theory calculations to systematically investigate the effects of halogenation on the bulk solid-state energetics of model anthradithiophene (ADT) materials, their interfacial energetics with C60, and the energetics of various ADT:C60blend compositions. In agreement with previous work, nonhalogenated ADT molecules show higher energy CT states in blends with C60and lower energy CT states in the ADT/C60bilayers. However, this trend is reversed in the halogenated ADT/C60systems, wherein the CT state energies of ADT:C60blends are lower than those in the bilayers. In bulk-heterojunction photovoltaics, the lower energy CT states present in the mixed phase with the halogenated ADT derivatives will likely decrease the probability of charge separation and increase charge recombination. The less favorable energy landscapes observed upon halogenation suggest that the benefits of fluorination observed in many OPV material systems may be more due to morphological factors.

Purpose:To describe the ophthalmic outcomes and complications after silicone oil (SO) removal. Methods:This nonrandomized retrospective review comprised patients who had SO removal from January 2020 to December 2022. Data collected included patient demographics, visual acuity (VA), intraocular pressure (IOP), initial tamponade, indication for SO placement, duration of SO in the eye, indication for SO removal, cataract progression, rates of retinal redetachment, cornea-related complications, additional surgical interventions, and other complications. Results:The study comprised 107 eyes (mean age, 56.6 years; 67% male). The most common indications for SO tamponade were rhegmatogenous retinal detachment (RRD), RRD with proliferative vitreoretinopathy (PVR), and tractional RD. The mean SO tamponade duration was 9.3 months and was longer for patients who did not have redetachment than for those who had detachment (10 months vs 6.8 months; P= .024). The mean preoperative logMAR VA had significantly improved by the final follow-up (1.44 vs 1.19; P< .001). The mean IOP was 16.43 mm Hg preoperatively and 16.81 mm Hg at the final visit (P= .672). Retinal redetachment occurred in 20.6% of patients, and the anatomic success rate at the final follow-up was 86.0%. A history of recurrent detachment and PVR was not associated with increased rates of postoperative redetachment. The overall rate of hypotony was 3.7% and of ocular hypertension, 7.5%. Significant cataract progression occurred in 69% of eyes. Conclusions:After SO removal, there was an overall improvement in VA and a stable IOP. Cataract progression was the most common complication. Although there is a risk for redetachment after SO removal, it may not have a detrimental effect on redetachment rates with a longer duration of SO tamponade.

ABSTRACTPolysorbates (PSs) are a class of surfactants commonly used in the formulation of protein therapeutic agents to provide protection against denaturation and aggregation. When the PS in these drug formulations degrades, loss of stabilization of the protein therapeutic and formulation may occur, resulting in particulate formation or other undesirable changes in product critical quality attributes. Here, we present a simplified platform to predict long-term PS20 and PS80 degradation for monoclonal antibody drugs containing the PS-degrading enzyme lysosomal acid lipase. The platform was based on a temperature-dependent equation derived from existing PS20 degradation stability data. Accurate prediction of both PS20 and PS80 hydrolysis for as long as 2 years was achieved through short-term kinetics studies performed within 2 weeks. This platform substantially shortens the time required to determine the long-term stability of PS degradation and therefore can be used to guide the purification process and optimization of antibody formulations.

Metal halide perovskite nanocrystals (NCs) are attractive materials for optoelectronics. However, further improvements in stability, reproducibility, and photoluminescence quantum yield (ΦPL) are essential for enabling future applications. Inadequate surface passivation is a major cause of instability, irreproducibility, and less than unity ΦPL. Herein, we probe the influence of multiple ligand binding groups on the colloidal stability and ΦPLof CsPbBr3nanocrystals (NCs). We find that post-synthetic treatment with dodecanethiol reproducibly yields highly stable NCs with near-unity ΦPLfor a range of synthetic conditions and initial ΦPLof the as-synthesized NCs. A mechanistic investigation shows that thiol addition leads to thioether formation via the thiol–ene reaction with octadecene, oleic acid, and oleylamine. Both thiolates and thioethers are suspected to bind to undercoordinated Pb atoms on the NC surfaces, and this surface binding can be rapidly accelerated through exposure to blue or UV light. Furthermore, we show that metallic Pb nanoparticles appear in many batches of synthesized CsPbBr3NCs and that dodecanethiol addition eliminates these metallic Pb particles.

Photon upconversion employing semiconductor nanocrystals (NCs) makes use of their large and tunable absorption to harvest light in the near-infrared (NIR) wavelengths as well as their small gap between singlet and triplet excited states to reduce energy losses. Here, we report the highest QY (11.8%) thus far for the conversion of NIR to yellow photons by improving the quality of the PbS NC. This high QY was achieved by using highly purified lead and thiourea precursors. This QY is 2.6 times higher than from NCs prepared with commercially available lead and sulfide precursors. Transient absorption spectroscopy reveals two reasons for the enhanced QY: longer intrinsic exciton lifetimes of PbS NCs and the ability to support a longer triplet lifetime for the surface-bound transmitter molecule. Overall, this results in a higher efficiency of triplet exciton transfer from the PbS NC light absorber to the emitter and thus a higher photon upconversion QY.

Fully fluorinated perfluorocarbon ligands are shown to modify the energetics and dielectric environment of quantum dots (QDs), resulting in a large hypsochromic shift in the optical gap. The original oleic acid (OA) ligands on PbS QDs can be completely replaced with thiolate and carboxylate-based perfluorocarbons, e.g., -SCF3and CF3(CF2)14COOH (pFA), respectively. Ultraviolet photoelectron spectroscopy indicates that the work function varies by >1.3 eV depending on the electronegativity of the surface ligand, while cyclic voltammetry shows that an OA:pFA ratio of ∼2:1 increases the oxidation potential by 0.18 eV in solution. The diminished reduction potential of the conduction band is confirmed by photoinduced electron transfer experiments. The short thiolate ligands, -SCF3and -SCH3, enhance the electron-donating ability of PbS QDs up to 7-fold because of an increase in the permeability of the ligand shell. This work shows that electron-withdrawing halogens like fluorine and chlorine can control the bandgap and band offsets of nanocrystals for the future design and optimization of functional organic/inorganic hybrid nanostructures.

Organometal halide perovskite photovoltaics typically contain both electron and hole transport layers, both of which influence charge extraction and recombination. The ionization energy (IE) of the hole transport layer (HTL) is one important material property that will influence the open-circuit voltage, fill factor, and short-circuit current. Herein, we introduce a new series of triarylaminoethynylsilanes with adjustable IEs as efficient HTL materials for methylammonium lead iodide (MAPbI3) perovskite based photovoltaics. The three triarylaminoethynylsilanes investigated can all be used as HTLs to yield PV performance on par with the commonly used HTLs PEDOT:PSS and Spiro-OMeTAD in inverted architectures (i.e., HTL deposited prior to the perovskite layer). We further investigate the influence of the HTL IE on the photovoltaic performance of MAPbI3based inverted devices using two different MAPbI3processing methods with a series of 11 different HTL materials, with IEs ranging from 4.74 to 5.84 eV. The requirements for the HTL IE change based on whether MAPbI3is formed from lead acetate, Pb(OAc)2, or PbI2as the Pb source. The ideal HTL IE range is between 4.8 and 5.3 eV for MAPbI3processed from Pb(OAc)2, while with PbI2the PV performance is relatively insensitive to variations in the HTL IE between 4.8 and 5.8 eV. Our results suggest that contradictory findings in the literature on the effect of the HTL IE in perovskite photovoltaics stem partly from the different processing methods employed.

The development of metal halide perovskite/perovskite heterostructures is hindered by rapid interfacial halide diffusion leading to mixed alloys rather than sharp interfaces. To circumvent this outcome, we developed an ion-blocking layer consisting of single-layer graphene (SLG) deposited between the metal halide perovskite layers and demonstrated that it effectively blocks anion diffusion in a CsPbBr3/SLG/CsPbI3heterostructure. Spatially resolved elemental analysis and spectroscopic measurements demonstrate the halides do not diffuse across the interface, whereas control samples without the SLG show rapid homogenization of the halides and loss of the sharp interface. Ultraviolet photoelectron spectroscopy, DFT calculations, and transient absorbance spectroscopy indicate the SLG has little electronic impact on the individual semiconductors. In the CsPbBr3/SLG/CsPbI3, we find a type I band alignment that supports transfer of photogenerated carriers across the heterointerface. Light-emitting diodes (LEDs) show electroluminescence from both the CsPbBr3and CsPbI3layers with no evidence of ion diffusion during operation. Our approach provides opportunities to design novel all-perovskite heterostructures to facilitate the control of charge and light in optoelectronic applications.