Increase In Conversion Efficiency Research Articles

Affordable excellence: unveiling the potential of graphitic carbon-based counter electrodes for high-performance dye-sensitized solar cells

Dye-Sensitized Solar Cells (DSSCs) have emerged as a promising alternative energy technology due to their minimal material requirements and straightforward production process, enabling efficient performance even under low-light conditions. Traditionally, high-performance DSSCs utilize platinum as the counter electrode. However, the high cost of platinum necessitates the development of more affordable counter electrodes that can match or surpass platinum-based counter electrodes (CEs) in conversion efficiency. This study investigates the synthesis and application of various cost-effective counter electrodes, including candle flame carbon soot, pencil lead graphite, and CS-coated PLG, in highefficiency DSSCs. For comparison, a platinum-based counter electrode is used as a benchmark. The working electrode comprises TiO2 on Fluorine-Doped Tin Oxide substrates. The DSSCs fabricated with counter electrodes such as PLG, CS, and CS-coated PLG exhibit efficiencies of approximately 6.2%, 3.5%, and 8.5%, respectively, compared to 10.8% for the Pt-based counter electrode. Reduced series resistance contributes to an improved Fill Factor and increased conversion efficiency. Furthermore, impedance spectroscopy reveals higher capacitance at the CE/electrolyte interface, enhancing charge collection efficiency and electron lifetime. Thus, the potential for significant improvement in conversion efficiency makes low-cost PLG and carbon-based electrodes a highly attractive alternative to Pt-based electrodes.

TEMPPERATURE AND IRRADIANCE EFFECTS, IN QUASI-STATIC REGIME, ON THE CONVERSION EFFICIENCYOF A BIFACIAL SILICON SOLAR CELL UNDER POLYCHROMATIC ILLUMINATION

In this work, a theoretical study of the effects of temperature and irradiance on a bifacial silicon solar cell is presented. To achieve this, the bifacial solar cell placed under polychromatic illumination, is the site of a photocreation of minority carriers whose movement is governed by the continuity equation. Solving this continuity equation allowed us to determine the density of the minority carriers photogenerated in the base of the cell as a function of temperature, irradiation and junction recombination velocity. From the expression of the minority carrier density, those of the photocurrent density, photovoltage, power and conversion efficiency have been deduced. When the ambient temperature of the medium varies from 290 K to 320 K, the power and efficiency of the solar cell decrease. On the other hand, for irradiance values between 100 W.m-2 and 400 W.m-2, we see an increase in power and conversion efficiency.

Defect Regulation of Low‐Temperature‐Processed CsPbI2Br Solar Cells Based on Silane Additives

The development of inverted all‐inorganic perovskite solar cells (PSCs) is limited by the defect‐induced nonradiative recombination. Herein, a strategy to enhance the efficiency and stability of p‐i‐n type CsPbI2Br solar cells by introducing (3‐glycidyloxypropyl)trimethoxysilane (GOPTS) into the CsPbI2Br precursor solution is reported. The incorporation of GOPTS significantly reduces voids and grain boundaries in CsPbI2Br films fabricated at low temperatures (150 °C). The alkoxy, epoxy, and ether groups in GOPTS effectively passivate uncoordinated Pb, diminishing the nonradiative recombination centers associated with perovskite defects. Density functional theory simulations suggest that GOPTS increases the vacancy formation energies of Cs and I, leading to the reduced nonradiative recombination. Furthermore, GOPTS mitigates photoinduced phase segregation and further enhances the performance and stability of the PSCs. This modification results in an increase in the power conversion efficiency of the p‐i‐n type CsPbI2Br solar cells, from 11.83% to 13.32%, when self‐assembled monolayers are used as the hole transport layer. This study underscores the potential of silane‐based additives in defect passivation for all‐inorganic perovskites, providing a viable route for the advancement of high‐efficiency CsPbI2Br solar cells.

Boosting Photovoltaic Efficiency: The Role of Functional Group Distribution in Perovskite Film Passivation.

The utilization of small organic molecules with appropriate functional groups and geometric configurations for surface passivation is essential for achieving efficient and stable perovskite solar cells (PSCs). In this study, two isomers, 4-sulfonamidobenzoic acid (4-SA) and 3-sulfamobenzoic acid (3-SA), both featuring sulfanilamide and carboxyl functional groups arranged in different positions, are evaluated for their effectiveness in passivating defects of the perovskite layer. The calculation and characterization results reveal that 3-SA, with its meta-substitution, offered superior passivation compared to the para-substituted 4-SA, leading to enhanced charge carrier dynamics and extraction efficiency. The devices treated with 3-SA demonstrates a notable increase in power conversion efficiency from 21.50% to 23.30%. Moreover, these devices maintain over 90% of their initial efficiency after 2000h in a 30% relative humidity environment, showcasing exceptional long-term stability. This research advances strategic design approaches for small molecule passivation, providing critical insights for the enhancement of perovskite optoelectronic applications.

Enhanced Performance and Stability of CsPbBr3 Perovskite Solar Cells Using Trioctylphosphine Oxide Additive.

This study investigates the application of trioctylphosphine oxide (TOPO) and triphenylphosphine oxide (TPPO) as an additive to enhance the performance of all-inorganic CsPbBr3 perovskite solar cells (PSCs). The addition of TOPO and TPPO passivates surface defects, increases grain size, and reduces surface trap states, leading to better light absorption and accelerated carrier transport. These modifications lead to an optimized energy level distribution, resulting in a significant increase in power conversion efficiency from 5.14 to 9.21% with TOPO and from 5.14% to 7.28% with TPPO. Furthermore, the long alkyl chains in TOPO provide effective isolation from air and water, significantly enhancing device stability for over 2400 h without packaging. The findings demonstrate that oxygen phosphine additives with long alkane chains are more effective in improving PSCs than those with aromatic hydrocarbons, offering new insights for the use of passivators in perovskite solar cells.

Enhancing FAPbI3 Perovskite Solar Cell Performance and Stability Through Bespoke Graphene Quantum Dots

ABSTRACTA novel approach to enhancing the efficiency and long‐term stability of perovskite solar cells (PSCs) is presented through strategic interfacial modification using bespoke graphene quantum dots (GQDs). GQDs with controlled alkylamine chain lengths, such as butylamine (C4), octylamine (C8), and dodecylamine (C12), were customized to have the proper optical and electronic properties toward specific interfaces within the PSCs. The incorporation of C4‐GQDs significantly improved the energy level alignment and conductivity of the SnO2 electron transport layer (ETL), while C12‐GQDs effectively reduced trap density on the perovskite surface, leading to enhanced defect passivation. These modifications resulted in a substantial increase in power conversion efficiency of 24.41% in a unit cell and 18.91% in a mini‐module, respectively. Notably, the maximum power point tracked perovskite mini‐module retained 89% of its initial efficiency during 1000 h of continuous light soaking condition at 25°C under 35% relative humidity. This work highlights the potential of bespoke GQDs to advance both the performance and durability of PSCs, providing a scalable approach for future photovoltaic applications. image

Dual Side Passivation Strategy with Multifunctional Organic Molecules for High Performance Wide Bandgap Perovskite Solar Cells

Perovskite-based tandem solar cells have received great attention, however, the wide bandgap (WBG) perovskite solar cell (PSC) used as the top layer still faces issues to overcome, including large open-circuit voltage (V OC) loss and halide segregation. Over the years, small organic molecules have been introduced at the interfaces between perovskite and charge transport layers to mitigate V OC losses, by passivating interfacial defects. Herein, we propose novel multifunctional organic molecules, i.e., octylammonium (OA) and N-methylsulfanilic acid (NMSA), at the top and bottom sides of perovskite light absorbing layer. We investigated the distinct roles of OA and NMSA components and examined the effects of passivation depending on the position of interfacial treatment such as bottom, top and dual sides of perovskite. It is observed that V OC deficits decreased from 0.58 V to 0.44 V, leading to the increase of the power conversion efficiency (PCE) from 16.24% to 19.83% for the 1.77 eV WBG PSCs. Furthermore, we demonstrate that halide segregation is significantly suppressed. The optimized WBG PSC maintained 98.9% of its initial PCE after 3300 seconds under 1-sun illumination, demonstrating enhanced maximum power point tracking stability. This study contributes to the development of next-generation high-performance PSCs, providing a deeper understanding of interfacial defect engineering.

Nanoscopic Observation of Perovskite Solar Cell with TEM

Recently, there has been a surge of interest in organometal halide perovskite solar cells (PSCs). These cells have exhibited a remarkable increase in power conversion efficiency (PCE), with certified PCEs reaching over 26% by employing mixed organic cations and halide anions. The PCE is significantly influenced by the photovoltaic properties of each component within the PSC.Despite the crucial role of crystallographic information, micro-structural analysis of the perovskite layer has not been extensively pursued. The micro-structural observation analysis of the perovskite layer with high resolution TEM is the most promising approach to understand the crystal structure. It has been widely accepted that the organometal halide perovskite exists in distinct phases: orthorhombic phase < 165K < tetragonal phase < 327K < cubic phase. However, our recent observations have revealed the coexistence of tetragonal and cubic phases at room temperature in conventional MAPbI3 thin film devices. Moreover, we have made the surprising discovery of superlattices comprising a mixture of tetragonal and cubic planes without any compositional alterations. The formation of these superlattices occurs through intrinsic structural transitions, without the need for artificial modifications. Consequently, many phenomena related to structural superlattices are anticipated to occur spontaneously and automatically within relevant contexts. Organometal halide perovskites demonstrate a remarkable ability to self-adjust their micro-structural configurations and self-organize buffer layers inside crystals or at hetero-interfaces by introducing self-assembled superlattices. We believe that this report represents a pivotal advancement, bringing PCEs of organometal halide perovskite solar cells closer to their theoretical maximum and redefining the potential of these materials for a wide range of applications beyond solar cells. Figure 1

Amidination of ligands for chemical and field-effect passivation stabilizes perovskite solar cells.

Surface passivation has driven the rapid increase in the power conversion efficiency (PCE) of perovskite solar cells (PSCs). However, state-of-the-art surface passivation techniques rely on ammonium ligands that suffer deprotonation under light and thermal stress. We developed a library of amidinium ligands, of interest for their resonance effect-enhanced N-H bonds that may resist deprotonation, to increase the thermal stability of passivation layers on perovskite surfaces. This strategy resulted in a >10-fold reduction in the ligand deprotonation equilibrium constant and a twofold increase in the maintenance of photoluminescence quantum yield after aging at 85°C under illumination in air. Implementing this approach, we achieved a certified quasi-steady-state PCE of 26.3% for inverted PSCs; and we report retention of ≥90% PCE after 1100 hours of continuous 1-sun maximum power point operation at 85°C.

Reconstruction of Hole Transport Layer via Co-Self-Assembled Molecules for High-Performance Inverted Perovskite Solar Cells.

Adjusting the hole transport layer (HTL) to optimize its interface with perovskite is crucial for minimizing interface recombination, enhancing carrier extraction, and achieving efficient and stable inverted perovskite solar cells (PSCs). However, as a commonly used HTL, the self-assemble layer (SAM) of [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl] phosphonic acid (MeO-2PACz) tends to form clusters and micelles during the deposition process, leading to inadequate coverage of the ITO substrate. Here, a Co-SAM strategy is employed by incorporating 4-mercaptobenzoic acid (SBA) and 4-trifluoromethyl benzoic acid (TBA) as additives into MeO-2PACz to fabricate a Co-SAM-based HTL. The introduced additive can interact with MeO-2PACz, facilitating cluster dispersion and thereby enabling better deposition on ITO for improved HTL coverage. Moreover, Co-SAM exhibits superior energy level alignment with perovskite to enhance interfacial contact and improve carrier extraction efficiency as well as promote growth of bottom perovskite grains. As a result, an impressive increase of the power conversion efficiency (PCE) from 21.34% to 23.31% is achieved in the inverted device based on the Co-SAM HTL of MeO-2PACz+TBA while maintaining ≈90% of its initial efficiency under continuous operation at 1-sun.

Piezoelectric effect promotes photoelectrochemical properties of 2D-3D ZnIn2S4/β-CdS strongly coupled interface

In the process of photoelectrochemical (PEC) hydrodecomposition, it is important to design photoelectrode materials with low cost, high charge separation efficiency and low charge recombination rate. Herein, 2D-3D strongly coupled ZnIn2S4/β-CdS nanocomposites were prepared by a two-step hydrothermal method. Meanwhile, the piezoelectric polarization was used to induce its generation of built-in electric field, which suppressed the secondary compounding of photogenerated charge carriers caused by the interfacial structural defects of the semiconductor heterojunction. The results show that ZnIn2S4/β-CdS has better photoelectrochemical decomposition ability of water under ultrasound, and its photocurrent density increases with the increase of ultrasound frequency, reaching a maximum value of 0.46 mA·cm−2 at 1.23 VRHE, which is 3.5 times higher than that before ultrasound. In addition, by comparing the significant increase of photocurrent conversion efficiency under the applied bias voltage before and after ultrasound, it can be concluded that the enhanced catalytic activity of ZnIn2S4/β-CdS is attributed to the efficient coupling effect between ZnIn2S4 and β-CdS under ultrasound conditions. This coupling effect enables the fast electron transfer at the interface between ZnIn2S4 and β-CdS. Consequently, this strongly coupled nanocomposite will provide inspiration for further construction of nanocomposites for photocatalytic decomposition of water.

Improving the Efficiency of Semitransparent Perovskite Solar Cell Using Down-Conversion Coating.

Perovskite solar cells (PSCs) have demonstrated exceptional efficiency, yet surpassing theoretical performance limits requires innovative methodologies. Among these, down-conversion techniques are pivotal in reducing optical losses and enhancing energy conversion efficiency. In this study, optical modeling, including a generalized transfer-matrix optical model, was employed to meticulously assess optical losses in semitransparent PSCs illuminated from the front and rear sides of the device. To reduce these losses, two down-conversion layers, made of N,N-diphenyl-4-(1,2,2-triphenylethenyl)-benzenamine and 4-(N,N-diphenylamino)benzaldehyde mixed with polymeric binder, were developed, showcasing initial photoluminescence quantum yields of 60% and 50% as films, respectively. The materials luminescence relies on the effect of aggregation-induced emission, which enhances the fluorescence of the dyes within the binder, providing their films with a unique behavior beneficial for photovoltaic applications. An optimization of these layers was performed, which aimed to reduce UV optical losses by adjusting the film thickness atop the PSCs. The refined down-conversion layers yielded a notable increase in the power conversion efficiency by approximately 0.4% for both the front and rear sides of the PSCs, demonstrating their significant potential in pushing the boundaries of solar cell performance.

Hydroxymethylfurfural(HMF): Exploring its potential as a wood resin derived from cellulose

As the demand for sustainable materials continues to rise, the development of innovative and renewable resins has become a central area of research. This study explores the creation of hydroxymethylfurfural (HMF) resin derived from cellulosic glucose extracted from finely powdered greens and fruit peels. Characterization of HMF was performed using NMR and FTIR-ATR, confirming the presence of HMF. The crude HMF resin underwent purification through crystallization, resulting in an increased conversion efficiency from 51 % to 92 %. The resin displayed high moisture resistance and enhanced bond strength in HMF/wood composites when subjected to boiling water. Morphological analysis revealed an absence of voids, and the HMF/wood composite exhibited a notable tensile strength of 21.5 MPa, comparable to other phenolic composites. The novelty of this work lies in the use of sustainable, powdered waste greens and fruit peels low-cost biomass sources for HMF production, offering a promising renewable alternative to traditional synthetic resins with improved performance characteristics.

Direct Laser Interference Patterning of Fluorine‐Doped Tin Oxide as a Pathway to Higher Efficiency in Perovskite Solar Cells

AbstractImproving light‐trapping capabilities through surface microstructuring of transparent conductive oxides is a promising approach to enhance solar cell efficiency. This study focuses on treating fluorine‐doped tin oxide (FTO) thin films using four‐beam direct laser interference patterning (DLIP) to create dot‐like periodic surface microstructures. The surface analysis using scanning electron microscopy and confocal microscopy reveals the presence of a periodic square grid of microcraters with a spatial period of ≈700 nm and an average depth ranging between 4 and 18 nm. These structures enhance the dispersion of incoming light up to 1000% in the visible and NIR spectra. When integrated into metal halide perovskite solar cells, FTO films patterned using low fluence conditions lead to a notable increase in the power conversion efficiencies (PCEs) compared to those made using untreated FTO. Importantly, preliminary stability tests on devices based on patterned FTO substrates show significantly improved stability compared to those fabricated using reference unpatterned substrates. These findings demonstrate that a DLIP treatment of FTO substrates is a promising technique that can substantially enhance the efficiency and stability of perovskite photovoltaic devices.

Enhanced the efficiency of carbon based perovskite solar cells via g-C3N4 as functional additives

The quality of perovskite layer plays an important role in the performance of perovskite solar cells. Various defects can arise during the crystal growth process of Perovskite thin film. However, by using additives. It is possible to effectively enhance crystallize and form high-quality perovskite films with improved morphology. g-C3N4, a carbon–nitrogen ring with delocalized π electrons and certain conductivity, facilitates the transport of charge carriers. When it is utilized as an additive in perovskite solar cells, g-C3N4 not only improves the quality and crystallinity of perovskite films, but also passivates defects. As a result of these improvements, the optimal efficiency for preparing carbon-based perovskite solar cells is 13.74 %. This represents a significant increase in photoelectric conversion efficiency from 10.39 % to 13.74 %, corresponding to a remarkable enhancement of 32.24 %. These findings provide valuable insights into the potential application of two-dimensional materials and carbon nitrogen ring for enhancing the performance of perovskite solar cells.

The advantages of employing i-a-SiOX:H as a buffer layer in hydrogenated amorphous silicon oxide solar cells

Abstract This study focuses on a p-i-n single junction solar cell made of hydrogenated amorphous silicon oxide (a-SiOx:H), aiming to enhance solar cell efficiency by mitigating the impact of discontinuities and mismatches occurring at the i/p defect-rich interface between the window layer and the absorber layer. To address this concern, the impact of adding a thin i-a-SiOx:H buffer layer between the p-a-SiOx:H window layer and the i-a-SiOx:H active layer was investigated through numerical modeling using the AMPS-1D (Analysis of Micro-electronic and Photonic Structures) computer program. Implementing these changes led to a remarkable increase in conversion efficiency, rising from 5.714% to an impressive 8.929%. The increase in short-circuit current (JSC), however, is due to improved quantum efficiency at short wavelengths between 350 and 550 nm. Furthermore, enhancing the built-in potential (Vbi) at the i/p interface, combined with the buffer layer’s appropriate band gap energy, increases VOC (open-circuit voltage) from 850 to 993 mV. The substantial improvement in the fill factor (FF) from 63.1 to 83.1% can be largely attributed to the smoothed band offset, primarily facilitated by the presence of the buffer layer at the p/i interface, which led to more efficient extraction of photogenerated holes. To ensure effective usage of the buffer layer, the thickness of a-SiOx:H (buffer layer) varied between 3 nm and 9 nm, while the p-type doping concentration of the same layer was adjusted between 0 and 1020 cm−3. In summary, adding a 3 nm thick a-SiOx:H buffer layer with an intermediate band gap and with a p-type doping concentration (NA) below 1018 cm−3 at the i/p interface improves the electrical and optical properties of the p-i-n solar cells (EFF = 8.951%; VOC = 0.994 V; FF = 83.1%; JSC = 10.842 mA.cm−2).

Online application of the periodic linear regression method for daily monitoring of photovoltaic systems performance

This paper presents an analysis of the performance of photovoltaic (PV) systems using daily applications of the periodic linear regression method to the performance indicators Final Yield (YF) and Reference Yield (YR). The research was conducted on PV systems installed on rooftops and ground at the Federal Institute of Education, Science, and Technology of Goiás (IFG), Itumbiara Campus, from July 2022 to August 2023. The Energy Monitoring and Management Software (SMGE) was developed to calculate the performance indicators and perform linear regression to analyze the performance of the systems. The results demonstrate that the efficiency of the systems can be monitored by analyzing variations in the slopes of the linear regression lines. An increase in energy conversion efficiency was observed following the cleaning of the PV panels, as reflected in significant changes in the regression slopes. Additionally, natural events, such as rainfall, positively impacted system efficiency. These findings highlight the importance of proper maintenance of PV panels, whether through scheduled cleaning or natural events like rain.

Optimal performance of silicon nanowire solar cells under low sunlight concentration and their integration as bottom cells in III–V multijunction systems

Nanostructured silicon solar cells are designed to minimize costs through reduced material usage while enhancing power conversion efficiency via superior light trapping and shorter charge separation distances compared to traditional planar cells. This study identifies the optimal conditions for nanoimprinted silicon nanowire (SiNW) solar cells to achieve maximum efficiency under low sunlight concentration and evaluates their performance as bottom cells in III–V multijunction solar cell systems. The findings indicate that the SiNW solar cell reaches its peak performance at a concentration factor of 7.5 suns and a temperature of 40°C or lower. Specifically, the absolute conversion efficiency under these conditions is 1.05% higher than that under unconcentrated light. Compared to a planar silicon solar cell under identical conditions, the SiNW solar cell exhibits a 3.75% increase in conversion efficiency. Additionally, the SiNW single-junction solar cell, when integrated in series with a commercial lattice-matched InGaP/GaAs dual-junction solar cell, was tested under unconcentrated sunlight, specifically at one-sun, global air mass 1.5 condition, to assess its viability in one-sun multi-junction solar cell applications. The results suggest that a III–V upper subcell with a smaller active area than that of the SiNW subcell is optimal for maximizing current production, which is favorable to the cost reduction of the device. This hybrid configuration is particularly advantageous for terrestrial applications, such as electric vehicles, which demand lightweight, high-performance multijunction solar cell devices. Although the weight reduction of the characterized SiNW solar cell with a full silicon substrate compared to its planar solar cell counterpart is 1.8%, recommendations to increase this reduction to as much as 64.5% are discussed to conclude this paper.

Advancing stability in inverted polymer solar cells through accelerated xenon curing of the ZnO layer

This study delves into the profound implications of employing an intensive xenon lamp treatment with a rapid curing method completed within 4 min, to fabricate a ZnO layer. Subsequently, we applied a coating of PM6:Y6 as the active layer and utilized MoO3/Ag as the contact electrode, aiming to advance the efficiency of polymer solar cells (PSCs) through entirely room-temperature processes. Our investigation juxtaposes this xenon lamp treatment with the conventional hot plate method for annealing the ZnO layer, conducted at 180 °C for both 20 min and 4 min. Remarkably, our proposed xenon lamp treatment process not only promotes charge transfer but also exhibits enhancements of the lattice oxygen in the Zn-O layer. This innovative methodology of xenon treatment yields a notable increase in power conversion efficiency (PCE), achieving 14.55 %, compared to 13.71 % and 12.44 % for the ZnO layers annealed with a hot plate for 20 min and 4 min, respectively. Moreover, devices subjected to the 4-min xenon lamp treatment maintained 85 % (T85) of their original Power Conversion Efficiency (PCE) after enduring 500 h of one-sun aging measurement. These findings evoke optimism regarding the xenon treatment's potential to streamline the fabrication process, and provide a promising avenue for mitigating interface degradation while enhancing the stability of PSCs.

Incorporation of Gold Nanoparticle into ZnO Electron Transport Layer to Improve Performance of Hybrid Bulk Heterojunction Solar Cell

Abstract We have investigated the effect of localized surface plasmon resonance (LSPR) from gold nanoparticles incorporated into the electron transport layer (ETL) of zinc oxide (ZnO) on charge carrier transport in order to improve the performance of inverted hybrid bulk-heterojunction solar cells. Synthesis of gold nanoparticles capped by 3-mercaptopropionic acid (AuMPA) and oleylamine (AuOA) was carried out by use of the reduction method and the fabrication of solar cell device with the configuration of ITO/ZnO:AuNPs/P3HT:PCBM/PEDOT:PSS/Ag was done by spin coating and thermal evaporation techniques. The absorbance spectra show a plasmonic peak of AuMPA in solution at 521 nm, while AuOA has a plasmonic peak at 531 nm, with both solutions showing a red-wine color. In our investigation, the incorporation of AuMPA about 2.65wt% or AuOA about 3.5 wt% in the ZnAc solution is quite stable. With the addition of 1.77 wt% AuMPA, the fabricated devices show a significant improvement at short circuit condition (JSC) from 46.67 mA/cm2 to 83.11 mA/cm2, resulting in an increase in power conversion efficiency (PCE) from 5.64% to 9.00% under the illumination of 100 mW/cm2 simulated solar irradiation. While the AuOA addition of 2.65 wt%, the JSC increased from 22.67 mA/cm2 to 44.12 mA/cm2 along with an improvement of PCE from 2.71% to 5.32%. The experiment results suggest that the electron mobility or charge carrier transport to the indium tin oxide (ITO) cathode is improved by the local electric field enhancement around the zinc oxide (ZnO) electron transport layer due to the effect of gold nanoparticles (AuNPs).