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Perovskite solar cells (PSCs) have achieved boosted efficiency growth in the last decade by utilizing 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (spiro-OMeTAD). Various do...

Perovskite solar cells (PSCs) with state-of-the-art efficiencies contain thermally unstable methylammonium (MA). Avoiding MA molecules usually leads to a severe decrease in the cell efficiency. In this work, a novel ion liquid (simplified as NDAPBF4) possessing a pyridine cation and BF4− anion were introduced to improve the performance of MA-free PSCs. The ion liquid NDAPBF4 can optimize the grain growth of the perovskite, leading to reduced carrier traps. In particular, NDAPBF4 served as an n-type dopant and boosted the electron transportation in the perovskite films, which further suppressed the carrier non-radiative recombination at the interface between the perovskite and the electron transporting layer. Finally, PSCs with a Cs0.05FA0.95PbI3 perovskite film as the absorber achieved a remarkable efficiency of 21.25%, which was one of the highest MA-free inverted perovskite solar cells up to date. PSCs doped with NDAPBF4 also gave excellent stability, which preserved 95% and 94% of the initial efficiency after being aged for 1000 h and 500 h under room temperature and elevated temperature at 85 °C, respectively.

Employing low-dimensional perovskite has been proven to be a promising approach to enhance the efficiency and stability of perovskite solar cells. Here, thiopheniformamidine hydrochloride is introduced into CH

Conjugated polyelectrolytes (CPEs) have been successfully applied in organic photovoltaics and organic light-emitting diodes, and recently those with inorganic cations became to serve as a hole-transporting layer (HTL) in inverted perovskite solar cells (iPSCs), whereas the CPE HTL materials with organic cations are really limited. In this work, we design a CPE whose side-chains are end-capped by CH3NH3+ cations, the same cations as that in the perovskite layer. The CPE is found to be more compatible to the perovskite material, and shows stronger abilities to reduce the traps both at the surface and in the bulk of the perovskite layer, compared with the typical poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS). The resulting iPSC presents much improved photovoltaic properties and a better long-term stability, with a power conversion efficiency of 19.76%, which is the highest value ever reported for iPSCs based on CPE HTLs.

Here, the authors report a highly efficient integrated ideal-bandgap perovskite/bulk-heterojunction solar cell (IPBSC) with an inverted architecture, featuring a near infrared (NIR) polymer DTBTI-based bulk-heterojunction (BHJ) layer atop guanidinium bromide (GABr)-modified FA

A novel zwitterion named bethanechol chloride (BTCC) was introduced to simultaneously stabilize a Pb-I framework and passivate defects for efficient inverted perovskite solar cells. The BTCC-assisted device yielded an elevated power conversion efficiency of 20.45% with an open-circuit voltage of 1.14 V.

Quasi-two-dimensional (Q-2D) perovskites ((RNH3)2MAn−1PbnI3n+1, RNH3 represents the organic spacer (mostly phenethylammonium (PEA) and n-butylammonium (BA)) and MA = methylammonium) have shown great potential for application in solar cells due to their intrinsic stability, where the organic spacer dominantly determines the Q-2D perovskite ambient stability and device performance. Current studies merely concentrate on unary organic spacer Q-2D perovskites, either using BA or PEA. Herein, for the first time, we have successfully designed and fabricated (PEA1−xBAx)2MA3Pb4I13 binary spacer-based Q-2D perovskite films, and demonstrated that the device using binary organic spacer-based Q-2D perovskite films has substantially better performance than that using either of the unary organic spacer-based Q-2D perovskite films. The (PEA0.8BA0.2)2MA3Pb4I13 binary spacer device yields a maximum power conversion efficiency of 15.7%, which outperforms the efficiency record (12–14%) for unary spacer (PEA or BA) Q-2D perovskite devices. In particular, a peak open-circuit voltage of 1.21 V is achieved due to a non-radiative recombination loss of ∼100 mV, the lowest reported loss value for Q-2D perovskite devices. The high device performance results from binary-spacer-induced intensified film surface quality, preferable vertical orientation of crystals and improved film optoelectronic properties as well as obviously decreased device recombination losses. These findings open up a new avenue for the rational design of Q-2D perovskite materials with polynary organic spacer.

Exploring earth-abundant and cost-effective catalysts with high activity and stability for a hydrogen evolution reaction (HER) is of great importance to practical applications of alkaline water electrolysis. Here, we report on A-site Ba2+-deficiency doping as an effective strategy to enhance the electrochemical activity of BaCo0.4Fe0.4Zr0.1Y0.1O3−δ for HER, which is related to the formation of oxygen vacancies around active Co/Fe ions. By comparison with the benchmarking Ba0.5Sr0.5Co0.8Fe0.2O3−δ, one of the most spotlighted perovskite oxides, the Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ oxide has lower overpotential and smaller Tafel slope. Furthermore, the Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ catalyst is ultrastable in an alkaline solution. The enhanced HER performance originated from the increased active atoms adjacent to oxygen vacancies on the surface of the Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ catalyst induced by Ba2+-deficiency doping. The low-coordinated active atoms and adjacent oxygen ions may play the role of heterojunctions that synergistically facilitate the Volmer process and thus render stimulated HER catalytic activity. The preliminary results suggest that Ba2+-deficiency doping is a feasible method to tailor the physical and electrochemical properties of perovskite, and that Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ is a potential catalyst for HER.

Although great efforts have been devoted to enhancing the efficiency and stability of perovskite solar cells (PSCs), the performance of PSCs has been far lower than anticipated. Interface engineering is helpful for obtaining high efficiency and stability through control of the interfacial charge transfer in PSCs. This paper demonstrates that the efficiency and stability of PSCs can be enhanced by introducing stable α-CsPbI3 quantum dots (QDs) as an interface layer between the perovskite film and the hole transport material (HTM) layer. By synergistically controlling the valence band position (VBP) of the perovskite and the interface layer, an interface engineering strategy was successfully used to increase the efficiency of hole transfer from the perovskite to the HTM layer, resulting in the power conversion efficiency increasing from 15.17 to 18.56%. In addition, the enhancement of the stability of PSCs can be attributed to coating inorganic CsPbI3 QDs onto the perovskite layer, which have a high moisture stability and result in long-term stability of the PSCs in ambient air.

Exploring competent electrocatalysts for the oxygen evolution reaction (OER) is central to the development of a clean, reliable and emission-free hydrogen economy. Perovskites have been seen as promising OER electrocatalysts among all the potential candidates so far. Here, we introduced redox inactive Zr and Y ions to meliorate the redox capability of active ions and prepared BaCo0.5−xFe0.5−xZrxYxO3−δ (BCF(ZY)x, x = 0.0−0.2) oxides as efficient electrocatalysts for the OER. The catalyst of BCF(ZY)0.1 exhibits a higher OER activity (including disk activity, intrinsic activity and mass activity) and better durability than the gold-standard OER electrocatalyst IrO2 and the well-known Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) perovskite. The overpotential to deliver an electrode current density of 10 mA cm−2 of BCF(ZY)0.1 oxide is merely 0.32 V in 1 M KOH, and the intrinsic activity of BCF(ZY)0.1 is ∼52 times higher than IrO2. The outstanding electro-catalytic activity and stability of BCF(ZY)0.1 are attributed to the increased redox ability compared with BSCF, including the faster charge transfer process and much more facile adsorption of OH− and desorption of O2.

A delicate control of crystallization and morphology of perovskite absorbers is critical to obtain high performance hybrid perovskite solar cells (PSCs). Here, we have developed a novel crystallization strategy which involves hydration water induced intermediate phase formation under heat assisted spin-coating processing (HASP) to manipulate the morphology and grain size of perovskite films, and thus it can avoid the use of toxic and volatile antisolvents used in conventional one-step solution processes to make PSCs. During HASP, impressive morphological evolution of films occurs with the formation of CH3NH3PbI3·xH2O perovskite intermediate phases. With ingenious control of the crystallization kinetics, highly crystalline perovskite films with fewer defect states and high carrier lifetimes are obtained. The corresponding PSCs exhibit a power conversion efficiency (PCE) of 19.12% with a stabilized power output efficiency of 18.89% at the maximum power point, which is a 70% enhancement compared to that of conventional one-step process based PSCs. Furthermore, the PSC fabricated by the HASP method achieved a PCE of 15.47% with an active area of 1.2 cm2. Moreover, the flexible PSCs fabricated by the HASP method achieved a record efficiency of 14.87% with negligible hysteresis for PEDOT:PSS-based flexible inverted PSCs. Our work opens up a new avenue for morphology and crystallization control through hydration water induced intermediate phase formation under HASP, which paves the way toward further enhancing the device performance of perovskite solar cells.

Two novel hole transporting materials (HTMs) bearing thermally cross-linkable styryl groups were developed and applied for perovskite solar cells. These HTMs could be in situ cross-linked under mild temperature. The resulted cross-linked HTMs form smooth, solvent-resistant films, which enables the subsequent spin-coating of perovskite layer. In addition, the fluorination approach successfully leads to strong interactions between HTM, formamidine (FA) and lead in perovskite, resulting in the passivation of the perovskite film. The device using the HTM with fluorine moieties (HTM-F) showed higher power conversion efficiency (PCE) of 20.51% than that of the device using fluorine-free HTM (HTM-H) of 19.07%. Moreover, the device with HTM-F exhibits better stability, retaining 90% of the initial PCE after 2000 h under ambient air and 91% of the initial PCE after 1000 h under 85 °C heating.

Owing to its high wettability and the resulting compatibility with the future industrial device fabrication process, the conjugated polyelectrolyte (CPE) has becoming a promising hole-transporting material (HTM) in the inverted perovskite solar cell (iPSC); however, only a few highly efficient CPEs have been reported probably due to the limited pool of molecular designing strategies. Here we construct a CPE named DTB(Na) with the same main-chain of a polymer DTB(EH) that was previously employed as a dopant-free HTM in a highly efficient regular type PSC (rPSC) and with simple water/alcohol soluble side-chains. Compared with its analog bearing the only variation of less thiophene units in the main-chain, DTB(Na) shows stronger capacities of hole-extraction and defect-passivation, which should be ascribed to the more intensive exposure of thiophene functional unit to the perovskite layer. As a result, the DTB(Na) iPSC device presents enhanced values on all the photovoltaic parameters and long-term stability, and a power conversion efficiency of 19.92% is realized. Our results demonstrate the feasibility for efficient polymeric HTMs in rPSCs and iPSCs to share the same main-chains, thus enriching the molecular designing strategies and probably expanding the library of efficient HTMs for iPSCs.

An optimized charge transporting layer (CTL) under perovskite film is crucial for efficient photoelectric devices. Here, a new water-soluble conjugated polyeletrolyte (CPE) with CH3 NH3+ (MA+ ) counterion termed as TB(MA) is used as the hole transporting layer (HTL) instead of the acidic poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) in sky-blue perovskite light-emitting diodes (PeLEDs). The inherent hydrophilicity of CPE enables a well-growth of quasi-2D perovskite layer with uniform and compact morphology, enhanced crystallinity with rare defect density and excellent energy transfer, resulting in a high photoluminescence quantum yield (PLQY) up to 62.0%. Especially, the MA+ counterion is able to passivate the interfacial defects in the perovskite, which optimize the interfacial compatibility between HTL and perovskite film. Finally, efficient sky-blue PeLEDs, emitting at 488 nm, are fabricated with high external quantum efficiency (EQE) up to 13.5% by using CPE as HTL. In addition, due to the low-temperature processability of water-soluble CPE, an efficient flexible sky-blue PeLEDs based on PEN/ITO substrate is also obtained with high EQE of 8.3%. Using CPE as HTL is an effective strategy toward fabricating efficient blue PeLEDs.

1.5-1.6 eV bandgap Pb-based perovskite solar cells (PSCs) with 30-31% theoretical efficiency limit by the Shockley-Queisser model achieve 21-24% power conversion efficiencies (PCEs). However, the best PCEs of reported ideal-bandgap (1.3-1.4 eV) Sn-Pb PSCs with a higher 33% theoretical efficiency limit are18%, mainly because of their large open-circuit voltage (V

Side-chain polymers have the potential to be excellent dopant-free hole-transporting materials (HTMs) for perovskite solar cells (PSCs) because of their unique characteristics, such as tunable energy levels, high charge mobility, good solubility, and excellent film-forming ability. However, there has been less research focusing on side-chain polymers for PSCs. Here, two side-chain polystyrenes with triphenylamine substituents on carbazole moieties were designed and characterized. The properties of the side-chain polymers were tuned finely, including the photophysical and electrochemical properties and charge mobilities, by changing the positions of triphenylamine substituents on carbazole. Owing to the higher mobility and charge extraction ability, the polymer P2 with the triphenylamine substituent on the 3,6-positions of the carbazole unit showed higher performance with power conversion efficiency (PCE) of 18.45%, which was much higher than the PCE (16.78%) of P1 with 2,7-positions substituted. These results clearly demonstrated that side-chain polymers can act as promising HTMs for PSC applications and the performance of side-chain polymers could be optimized by carefully tuning the structure of the monomer, which provides a new strategy to design new kinds of side-chain polymers and obtain high-performance dopant-free HTMs.

In order to realize the real navigation behavior of virtual human, a new method is proposed to integrate the psychological emotion, sociological role and personality characteristics of virtual human into the collision avoidance behavior, so as to generate diversified collision avoidance behavior according to different internal attributes of virtual human. Based on the principle of minimum cost, the influences of psychological emotion, sociological role and personality parameters on the parameters of predictive collision avoidance behavior are studied. Finally, the relationship between the fuzzy reasoning method and the predictive collision avoidance behavior parameters is established. The simulation results show that our approach is effective and feasible. Eventually realistic crowd phenomena are created in the scenarios in city environment.

Two novel electron-rich linear small-molecules, containing benzene and thiophene as the cores with arylamine side groups, named HTM1 and HTM2, respectively, were synthesized via short, easy and efficient synthetic routes. The influence of the π-linkers of the two materials on photophysical, electrochemical, and thermal properties, and hole mobility and photovoltaic performance was investigated. The compound with thiophene as π-linker (HTM2) shows better solubility and higher hole-transporting mobility than the compound with benzene as π-linker (HTM1). When these two materials were incorporated into perovskite solar cells as hole transporting materials (HTMs), short circuit photocurrent densities (Jscs) of 15.83 mA cm−2 and 21.1 mA cm−2, open circuit voltages (Vocs) of 0.79 V and 1.09 V, and fill factors (FFs) of 0.46 and 0.62, were obtained. These factors contributed to average overall power conversion efficiencies (PCEs) of 6.4% and 13.9% with the best PCEs of 7.5% and 14.7%, respectively. The performance of HTM2 is comparable to the PCE obtained using the current state-of-the-art HTM of 2,2′,7,7′-tetrakis(N,N′-di-p-methoxyphenylamine)-9,9′-spirobifluorene (spiro-OMeTAD) with the best PCE of 17.4% using a similar device preparation method and measurement conditions. These results showed that selecting a suitable π-linker is important for the performance of HTMs. And the simple HTM2 material is a promising HTM with the potential to replace the expensive spiro-OMeTAD due to its comparable performance with a much simpler synthesis route and much reduced cost (10 times less than that of spiro-OMeTAD). This study demonstrates that a compound with a suitable π-linker could be a low-cost and high performance HTM to replace spiro-OMeTAD.

Hard carbon exhibits high theoretical capacity for sodium-ion batteries. However, its practical application suffers from low electric conductivity, poor electrochemical stability, and sluggish kinetics. To tackle these challenges, novel nitrogen-doped carbon spheres with mesopores, ultrathin nanostructure, and optimal graphitization are prepared by a three-step procedure. We find that the as-prepared sample (NMCSs-800) with an optimal structure and nitrogen content delivers a high reversible sodium storage capacity of 334.7 mA h/g at 50 mA/g and an ultrahigh rate performance of 93.9 mA h/g at 5 A/g, which is better than most state-of-the-art carbon materials. The improved energy storage capacity is attributed to its unique architecture and optimal nitrogen doping, which provide abundant active sites, defects, and voids. Moreover, kinetic analysis and in situ Raman spectroscopy results reveal adsorption and adsorption-intercalation mechanisms for Na

Exploring earth-abundant and cost-effective catalysts with high activity and stability for a hydrogen evolution reaction (HER) is of great importance to practical applications of alkaline water electrolysis. Here, we report on A-site Ba2+-deficiency doping as an effective strategy to enhance the electrochemical activity of BaCo0.4Fe0.4Zr0.1Y0.1O3−δ for HER, which is related to the formation of oxygen vacancies around active Co/Fe ions. By comparison with the benchmarking Ba0.5Sr0.5Co0.8Fe0.2O3−δ, one of the most spotlighted perovskite oxides, the Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ oxide has lower overpotential and smaller Tafel slope. Furthermore, the Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ catalyst is ultrastable in an alkaline solution. The enhanced HER performance originated from the increased active atoms adjacent to oxygen vacancies on the surface of the Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ catalyst induced by Ba2+-deficiency doping. The low-coordinated active atoms and adjacent oxygen ions may play the role of heterojunctions that synergistically facilitate the Volmer process and thus render stimulated HER catalytic activity. The preliminary results suggest that Ba2+-deficiency doping is a feasible method to tailor the physical and electrochemical properties of perovskite, and that Ba0.95Co0.4Fe0.4Zr0.1Y0.1O3−δ is a potential catalyst for HER.

Modified 3,4-ethylenedioxythiophene is employed as the conjugated side chain in conjugated polymers, which can significantly depress the dark current of the polymer photodetectors with little associated decrease in photovoltaic properties, thus enhanceing the detectivities. This approach can be applied to a variety of conjugated polymers covering a photoresponse range from UV to NIR.

Highly efficient noble-metal-free electrocatalysts are urgently explored for high energy density and safe metal-air batteries. Herein, an ingenious Co-Co3O4@NAC is prepared for this purpose by anchoring Co single atom on both Co3O4 nanoparticle and nitrogen-doped active carbon (NAC), where synergistic interaction among Co atoms, Co3O4 particles and NAC plays a significant role for excellent oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Moreover, the primary zinc-air battery (ZAB) with the Co-Co3O4@NAC as a cathode catalyst shows a high open circuit voltage (OCV) of 1.449 V, a specific energy density of 721 mA h/g and a maximum power density of 164 mW/cm2. The rechargeable ZAB with this catalyst displays a low voltage gap of 0.773 V at 10 mA/cm2 and stable cycling performance. This work provides a novel tactic to design elaborate high-efficient and promising bifunctional catalysts with non-noble metal atom and metal oxide for metal-air batteries.

The surface defects and grain boundary defects of organometallic halide perovskite films are detrimental to both the efficiency and stability of perovskite solar cells (PSCs). Furthermore, the electrical conductivity, work function and surface morphology of the hole transport layer (HTL) can also affect the performance of PSCs significantly. Here, we first have developed a novel synergistic strategy that uses multiple functional EMIC (1-Ethyl-3-methylimidazolium chloride) ionic liquid to modify PEDOT:PSS (poly (3, 4-ethylenedioxythiophene) polystyrene sulfonate) HTL, thereby obtaining the HTL with high electrical conductivity, low work function and smooth surface. Moreover, a novel S-acetylthiocholine chloride molecule which replaces expensive PCBM (phenyl-C61-butyric acid methyl ester) is developed to effectively passivate the negative- and positive-charged ionic defects in hybrid perovskite. The synergistic strategy extends the carrier recombination lifetime and reduces the charge trap density. In addition, the current hysteresis of the inverted device was also effectively eliminated. As a result, the champion cell in small area shows 20.06% efficiency with no hysteresis, along with an efficiency 18.77% for inverted PSCs in an active area of 1 cm2, both of which are the highest efficiency in the one-step PEDOT:PSS-based inverted PSCs so far. Compared to PCBM, the device passivated by S-acetylthiocholine chloride also has improved environmental stability (retaining 85% of initial PCE after 35 days storage without encapsulation in air with 60% humidity) and thermal stability (retaining 87% of initial PCE after 80 °C for 24 h storage without encapsulation under inert atmosphere).

Mono- and bis-stannylation at the chain ends of regioregular poly(3-hexylthiophene) (P3HT) were conducted by post-functionalization of P3HT synthesized through Ni-catalyzed Grignard metathesis polymerization. Lithiation of P3HT with s-BuLi and subsequent stannylation with Me3SnCl led to the formation of bis-stannylated P3HT. The highest conversion of 81% was achieved with the additive N,N,N′,N′-tetramethylethylenediamine (TMEDA), which could enhance the stability of the lithiated compound. On the other hand, mono-stannylated P3HT was synthesized without contamination by bis-stannylated P3HT through successive reactions with a Grignard reagent and Me3SnCl.

A synthetic route was developed to introduce an electron accepting unit, 2,5-di(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4-dione (DPP), into the main chain of regioregular poly(3-hexylthiophene) (P3HT)...

A variety of dopant-free hole-transporting materials (HTMs) is effectively applied in perovskite solar cells (PSCs); however, HTMs with the additional function of HTM/perovskite interfacial optimization that is crucial to their photovoltaic performance are really limited. In this work, the design of an HTM bearing an intensive exposure of its functional aromatic rings to perovskite layer via side-chain engineering is attempted. With an edge-on orientation and a short distance to perovskite, this HTM was expected to display an excellent ability to extract holes from and passivate defects in the perovskite layer. To demonstrate this strategy, an alternating copolymer was constructed with a 2,5-di-2-ethylhexyloxy-1,4-phenylene unit and a bithiophene unit, and the PSC based on this polymer showed an ultrahigh short-circuit current density of 25.50 mA cm-2 , which was the highest so far presented by dopant-free organic HTMs. A comparable power conversion efficiency of 19.68% (certified: 19.5%) to that of a control 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) device (19.81%) was thus obtained, which is the highest value ever reported for mesoporous PSCs based on dopant-free polymeric HTMs.

A mesoporous TiO2 film consisting of different size nanocrystal particles without any organic binder was prepared on a conductive indium−tin oxide (ITO)-coated polyethylene naphthalate (PEN) plasti...

A mesoporous nanocrystalline graded TiO 2 film was prepared on either a transparent conductive glass (ITO/glass) or a transparent conductive polymer (ITO/PEN, PEN = poly(ethylene naphthalene-2,6-dicarboxylate) through a doctor-blade method and then treated by chemical sintering at 150 °C. The graded film, which has a large specific surface area, high porosity, and proper strength, was composed of particles with different sizes and appropriate ratios. The effects of the smallest particles for binding and the largest particles for light scattering were studied. High light-to-energy conversion efficiencies of 4.10% and 3.05% were obtained within the dye-sensitized solar cells (DSSCs) fabricated by using the graded films on ITO/glass and ITO/PEN, respectively. The results show that the graded structure has promising applications in DSSCs.

Titanate nanotubes with an outer diameter of ca. 9 nm were obtained with hydrothermal method followed by an ion exchange reaction. The as-prepared sample was composed of H 2 Ti 2 O 4 (OH) 2 , which was thermally unstable. The effect of calcination temperature on its morphology and crystal form was investigated. Based on the results, especially the appearance of lotus-root-like structures, the transformation mechanism was proposed, which involved the dehydrations of intralayered and interlayered OH groups. The decrease in the interlayer distance and the transformation from titanate to anatase were ascribed to the interlayered dehydration, while the destruction of nanotubes into particles was caused by the intralayered one.

Here, we firstly reported a composite electrolyte prepared by adding α-zirconium phosphate into the iodide/triiodide liquid electrolyte including 4-tert-butylpyridine (TBP). The obtained composite electrolyte exhibited very good electrochemical property. The exchange current density (I0) and the diffusion coefficient of triiodide (DI3-) were both enhanced markedly. It was proved that the intercalation behavior of TBP into layered α-ZrP could be responsible for their enhancement. The mechanism for the enhancement of I0 and DI3- were investigated in detail, supported by X-ray diffraction (XRD) electrochemical impedance spectra (EIS) and limiting current measurements. Keywords: Exchange current density, Diffusion coefficient, Zirconium phosphate, Electrolyte

A novel hexagonal two-dimensional ZnO nanosheet thin film was successfully synthesized on an aluminum substrate by a simple wet-chemical approach, which exhibited very strong orange emission. It was concluded that ZnO nanosheets were induced to grow along 〈−1 1 0 0〉directions by the boehmite layer formed on the surface of the aluminum substrate. In addition, the orange photoluminescence of the ZnO nanosheet film has been discussed in detail.