Structure Perovskite Solar Cells Research Articles

In situ artificial wide-bandgap Cs-based recrystallized-arrays for optical optimization of perovskite solar cells

Coordinated light management as one of the most essential strategies to further improve the power conversion efficiencies (PCEs) of perovskite solar cells (PSCs), which can achieve stronger light trapping, coupling and absorption through submicron nanostructured morphologies relative to planar structure. However, the interfacial preparation of textured-structures has been facing great challenges, which has severely limited the research progress in the field of optical structures of PSCs. Here, in situ growth of inorganic Cs-based perovskite recrystallized-arrays (CPRA) on the perovskite surface was realized by pseudo-halide anion solvent engineering. This preparation procedure of the CPRA is very facile and cost-effective. The induced recrystallization involved in the CPRA synthesis process is non-invasive to the underlying perovskite. It is experimentally and theoretically shown that highly recrystallized-arrays can provide excellent optoelectronic performance. The open circuit voltage (VOC) of the champion PSC modified by this wide-bandgap CPRA can exceed 1.20 V, and the PCE can reach 23.23%. Moreover, this scheme has the function of tuning the bandgap, which can increase the VOC of device up to 1.23 V (PCE 22.12%). The long-term stability of the CPRA-modified PSCs is also prominent based on the inherent lotus hydrophobic properties of the bionic arrays.

Irreversible phase back conversion of α‐FAPbI3 driven by lithium‐ion migration in perovskite solar cells

AbstractTypically n‐i‐p structured perovskite solar cells (PSCs) incorporate 2,2′,7,7′‐tetrakis (N,N‐di‐p‐methoxyphenyl amine)‐9,9′‐spirobifluorene (spiro‐OMeTAD) as the hole‐transporting material. Chemical doping of spiro‐OMeTAD involves a lithium bis(trifluoromethyl sulfonyl)imide dopant, causing complex side‐reactions that affect the device performance, which are not fully understood. Here, we investigate the aging‐dependent device performance of widely used formamidinium lead triiodide (FAPbI3)‐based PSCs correlated with lithium‐ion (Li+) migration. Comprehensive analyses reveal that Li+ ions migrate from spiro‐OMeTAD to perovskite, SnO2, and their interfaces to induce the phase‐back conversion of α‐FAPbI3 to δ‐FAPbI3, generation and migration of iodine defects, and de‐doping of spiro‐OMeTAD. The rapid performance drop of FAPbI3‐based PSCs, even aging under dark conditions, is attributed to a series of these processes. This study identifies the hidden side effects of Li+ ion migration in FAPbI3‐based PSCs that can guide further work to maximize the operational stability of PSCs.image

Hybrid Mesoporous TiO2/ZnO Electron Transport Layer for Efficient Perovskite Solar Cell.

In recent years, perovskite solar cells (PSCs) have gained major attention as potentially useful photovoltaic technology due to their ever-increasing power-conversion efficiency (PCE). The efficiency of PSCs depends strongly on the type of materials selected as the electron transport layer (ETL). TiO2 is the most widely used electron transport material for the n-i-p structure of PSCs. Nevertheless, ZnO is a promising candidate owing to its high transparency, suitable energy band structure, and high electron mobility. In this investigation, hybrid mesoporous TiO2/ZnO ETL was fabricated for a perovskite solar cell composed of FTO-coated glass/compact TiO2/mesoporous ETL/FAPbI3/2D perovskite/Spiro-OMeTAD/Au. The influence of ZnO nanostructures with different percentage weight contents on the photovoltaic performance was investigated. It was found that the addition of ZnO had no significant effect on the surface topography, structure, and optical properties of the hybrid mesoporous electron-transport layer but strongly affected the electrical properties of PSCs. The best efficiency rate of 18.24% has been obtained for PSCs with 2 wt.% ZnO.

Using machine learning for prediction of spray coated perovskite solar cells efficiency: From experimental to theoretical models

Low-cost perovskite solar cells (PSCs) have experienced unprecedented gains in power conversion efficiency (PCE) of up to 25% of lab-scale devices. To be realized in the market, however, PSCs are not only required to be efficient but also scalable in production. While spray coating has viability as an industrial manufacturing process for perovskite photovoltaics scaling, optimizing the spray conditions is often seen as a challenging and time-consuming process due to its complex and multidimensional parameters. Herein, we use a machine learning (ML) approach to capture the relationship between spray parameter settings to the resultant photoconversion efficiency (PCE) of PSCs from experimental collected data points. This data-driven approach has the potential to accurately predict PCE values given the manufacturing parameters, enabling optimization and resulting in an increased experimentally recorded PCE. Furthermore, we also used a Convolutional Neural Network (CNN) to predict defect size distributions in the PSC structures to improve the understanding of defect formation mechanism at given spray parameters. The implications of the results are discussed for optimizing spray manufacturing process of efficient perovskite photovoltaics.

Bowl-Assisted Ball Assembly for Solvent-Processing the C60 Electron Transport Layer of High-Performance Inverted Perovskite Solar Cell.

Pristine fullerene C60 is an excellent electron transport material for state-of-the-art inverted structure perovskite solar cells (PSCs), but its low solubility leaves thermal evaporation as the only method for depositing it into a high-quality electron transport layer (ETL). To address this problem, we herein introduce a highly soluble bowl-shaped additive, corannulene, to assist in C60 -assembly into a smooth and compact film through the favorable bowl-ball interaction. Our results show that not only corannulene can dramatically enhance the film formability of C60 , it also plays a critical role in forming C60 -corannulene (CC) supramolecular species and in boosting intermolecular electron transport dynamics in the ETL. This strategy has allowed CC devices to deliver high power conversion efficiencies up to 21.69 %, which is the highest value among the PSCs based on the solution-processed-C60 (SP-C60 ) ETL. Moreover, the stability of the CC device is far superior to that of the C60 -only device because corannulene can retard and curb the spontaneous aggregation of C60 . This work establishes the bowl-assisted ball assembly strategy for developing low-cost and efficient SP-C60 ETLs with high promise for fully-SP PSCs.

Bowl‐Assisted Ball Assembly for Solvent‐Processing the C60 Electron Transport Layer of High‐Performance Inverted Perovskite Solar Cell

AbstractPristine fullerene C60 is an excellent electron transport material for state‐of‐the‐art inverted structure perovskite solar cells (PSCs), but its low solubility leaves thermal evaporation as the only method for depositing it into a high‐quality electron transport layer (ETL). To address this problem, we herein introduce a highly soluble bowl‐shaped additive, corannulene, to assist in C60‐assembly into a smooth and compact film through the favorable bowl‐ball interaction. Our results show that not only corannulene can dramatically enhance the film formability of C60, it also plays a critical role in forming C60‐corannulene (CC) supramolecular species and in boosting intermolecular electron transport dynamics in the ETL. This strategy has allowed CC devices to deliver high power conversion efficiencies up to 21.69 %, which is the highest value among the PSCs based on the solution‐processed‐C60 (SP‐C60) ETL. Moreover, the stability of the CC device is far superior to that of the C60‐only device because corannulene can retard and curb the spontaneous aggregation of C60. This work establishes the bowl‐assisted ball assembly strategy for developing low‐cost and efficient SP‐C60 ETLs with high promise for fully‐SP PSCs.

Improved PCE in stable lead-free perovskite solar cells based on band engineering of ETL and absorber

In this paper, a unique structure of graded band gap (GBG) electron transport layer (ETL) based lead-free Perovskite solar cell (PSC) is proposed and numerically investigated. The structure consists of cesium Formamidinium tin iodide (FACsSnI3) with band-gap grading aspect sandwiched between electron and hole transport layers. Various ETLs such as Zn(S,O), ZnO, ZnMgO and C60 have been considered and investigated with and without GBG aspect. It is revealed that the use of band engineering based on band gap grading ETL and absorber films allows the dual-advantages of enhanced photogeneration and carrier extraction mechanisms. The merits of the proposed PSC structure are compared to other published results in terms of improved photovoltaic parameters. The obtained results show improvements in photoconversion properties of the PSCs when GBG-Zn(S,O) is considered as an ETL. The effective conduction band alignment of GBG-Zn(S,O)/GBG-FACsSnI3 heterostructure interface leads to an improved carrier collection efficiency and subsequently improved efficiency. The optimized PSC structure presents power conversion efficiency as high as 21.67 %, with an open circuit voltage of 0.96 V, short-circuit current of 30.75 mA/cm2, and fill factor of 72.88%. The obtained photovoltaic parameters of the proposed GBG-ETL/GBG-FACsSnI3 heterostructure can provide new perspectives for the realization of efficient cost-effective lead-free PSCs.

Performance evaluation and the optimization of an inverted photo-voltaic cell with lead-free double perovskite material and inorganic transport layer materials

The research on the solar cell structure based on various inorganic, organic and hybrid type of perovskite absorbing materials is increasing due to their legion features. Various inorganic titanium (Ti) based double perovskite absorbing materials like, Cs2TiCl6, Cs2TiBr6, and Cs2TiI6 are examined. Cs2TiBr6 is chosen to be the most promising absorbing layer material alternative suitable for a stable environmentally friendly solar cell application due to its larger spectrum response and tunable band gap than the other promising absorbing materials. The primary objective of this work aims for investigating the functioning of Cs2TiBr6 with various inorganic charge transport materials under simulated conditions using the simulation software, SCAPS-1D (a Solar Cell Capacitance Simulator), Solar Cell Capacitance Simulator, and its functioning is evaluated by varying the interface defect density, thickness, defect density, etc. of various layer materials of the solar cell device. The basic input parameters, like electron-affinity, thickness, band-gap, charge mobility, permittivity, and defect density, of different layer materials are used in the simulation software to accomplish the modelling of the novel structure of solar cell device. A highly efficient environmentally friendly perovskite solar cell structure is the focus of this numerical research. Analysis results are compared with the existing data for substantiation. Finally, one planar inverted, high performance device structure, Glass/MoO3/Cs2TiBr6/SnO2/Au, is evolved, which is a promising eco-friendly device that can be used for making solar panels without any toxic consequences. The short circuit current density, the open circuit voltage, power conversion efficiency, and the fill-factor of this innovative inverted solar cell structure are observed to be 16.589 mA/cm2, 1.1 V, 15.68 %, and 85.76 %, which are significantly better parameters than those previously reported.

SCAPS simulation and DFT study of lead-free perovskite solar cells based on CsGeI3

With the rapid development of perovskite solar cells (PSCs), environmentally friendly germanium-based PSCs have begun to appear in people's vision. We have designed a perovskite solar cell structure consisting of FTO/Cd0.5Zn0.5S/CsGeI3/MoO3/Au. Our study focused on analyzing the impact of various factors such as the absorption layer, electron transport layer (ETL), hole transport layer (HTL), interfacial defect layer (IDL), and temperature, on device performance. We optimized various parameters of the device, and as a result, the final PCE reached an impressive 35.91%. In addition, we conducted an analysis of the perovskite absorber layer using density functional theory (DFT) and investigated the function of Ge atoms in the perovskite absorber layer. The results show that, for HTL, altering the doping concentration of the ETL has a more significant impact on PSCs. When the operating temperature exceeds 300K, only the short-circuit current (Jsc) increases. When the defect density exceeds 1013cm−3, the rate of carrier recombination begins to increase significantly, along with the interface defect layer. We also analyzed the energy band, density of states, charge density difference, charge population, and elastic constants of the absorption layer using density functional theory (DFT). The results indicate that Ge atoms play a crucial role in photon absorption and photocurrent generation, which is a significant factor contributing to the high power conversion efficiency of germanium-based PSCs. Due to the transfer of electric charge from the Ge atom to the periphery of the I atom and the hybridization between the Ge-4p and I-5p orbitals, the Ge–I bond is formed and stabilized. Finally, the calculation of elastic constants shows that CsGeI3 is a stable mechanical structure.

Design and analysis of high-efficiency perovskite solar cell using the controllable photonic structure and plasmonic nanoparticles

Device modeling of CH3NH3PbI3 based controllable photonic structure and plasmonic nanoparticles perovskite solar cells (PSC) was performed. In recent years, light trapping (LT) and plasmonic structures in PSCs have been developed and attracted widespread attention and encouraged researchers to develop and test many architectures in this area. Also, using controllable photonic structures and plasmonic nanoparticles in PSCs significantly affect the power conversion efficiency (PCE). LT by photonic structure and also the interaction of incident light with plasmonic nanoparticles (NPs) is considered as a hopeful way to enhance the PCE of PSCs in this simulation. For accurate calculation and also considering all parameters on PSC, the present simulation is done using the finite element method (FEM). The simulation results showed that using a photonic structure significantly affects the photovoltaic result of the PSC, and the PCE reached from 15.62 % for the planar structure to 16.17 % for the photonic structure. Here, we concentrate on a significant aspect of nanostructures that minimizes light loss by optimizing and managing light to achieve high PCE for the PSC. Then we used plasmonic NPs at the top of the electron layer transfer (ETL), active layer, and hole transfer layer (HTL), and the best position to achieve the highest PCE was the top of HTL. Moreover, an additional layer as a complimentary layer (CH3NH3SnI3) was used to maximize efficiency with values of short circuit current (Jsc) 27.81 (mA/cm2), open circuit voltage (Voc) 0.949 (V), fill factor (FF) 81.77 % and PCE 21.85 %. Using these combined techniques opens horizons of improvement for the PCE of PSC.

Design of high efficiency perovskite solar cells based on inorganic and organic undoped double hole layer

The use of organic and inorganic double hole layers allows for efficient tuning of the matching of energy levels between each layer and improve the photovoltaic performance and stability of perovskite solar cells (PSCs). However, the cost of band matching for preparing perovskite cells is huge. In this paper, the effect of double hole layer on the performance of PSCs is analyzed by theoretical calculation, and an optimized structure of PSCs is proposed. The traditional Spiro-OMeTAD and MAPbI3 absorption layers are added with copper oxide (CuO) hole layers. The Solar Capacitor One-dimensional Tool (SCAPS) is used to simulate the relationship between the energy level matching of the hole layer and the photoelectric conversion efficiency (PCE) of the cell, and then the photovoltaic conversion performance is optimized accordingly. The results show a CuO hole layer with an energy gap of 1.5 can reduce the direct recombination of electron and hole pairs in the recombination layer, thereby increasing the filling factor (FF), while Spiro-OMeTAD can reduce electron recombination in the anode, thereby increasing short circuit current (Jsc). The FF and Jsc is increased simultaneously with the addition of a 200 nm CuO layer, which results in the increase of PCE from 16.82% to 21.82%. In addition, the absorption spectra and power density distributions of the two structures were calculated, and the mechanism of high absorption under different bands was explored. The effect of different material thickness and doping concentration on the photoelectric performance was studied, and the optimal parameters of the solar cell were determined, which increases the PCE by 5.95%. The cell structure proposed in this research can provide theoretical guidance for the development of such experiments and provide a novel design idea for structural optimization of PSCs.

Lead free CsSn0.5Ge0.5I3 perovskite solar cell with different layer properties via SCAPS‐1D simulation

AbstractOrganic–inorganic halide perovskite solar cells (PSCs) have been extensively studied due to their simple fabrication methods and obvious device efficiency advantages. In this work, the perovskite CsSn0.5Ge0.5I3 is used as the light absorption layer, which is doped with Ge2+ in CsSnI3 to improve its stability. The polymers of 3‐hexylthiophene (P3HT) with excellent optoelectronic properties and low price, and SnO2 with high electron extraction ability is selected as charge transport layers. Based on these, a novel PSC structure (FTO/SnO2/IDL1/CsSn0.5Ge0.5I3/IDL2/P3HT/Au) has been simulated via solar cell capacitor simulator (SCAPS‐1D). The PSC performance is optimized by adjusting a series of parameters, including the layer thickness, defect density, electron affinity potential energy, and operating temperature, and so forth. The results show that the PSC defects are passivated by adjusting the appropriate parameters, and the final optimized open circuit voltage (VOC) is 1.08 V, short‐circuit current density (JSC) is 27.37 mA/cm2, fill factor (FF) is 83.32%, while the power conversion efficiency (PCE) is increased from the initial 10.89% to 24.63%, which provides theoretical reference for experiments and new ideas for the preparation and development of efficient and environmentally friendly PSCs. Finally, the effect of different metal cathodes with and without hole transport layer (HTL) on PSC performance is compared. The PSCs without HTL are more dependent on battery cathodes, which provided a way to replace precious metals with other electrode materials.

Optimizing the performance of Ge-based perovskite solar cells by doping CsGeI3 instead of charge transport layer

In recent years, Ge-based perovskite solar cells (PSCs) have gradually become a shining star in the field of scientific research because of their high conductivity. However, the defects between battery layers seriously affect the transmission efficiency of carriers. Therefore, we doped CsGeI3 instead of the original charge transport layer to passivate the defects of the battery. We created p-CsGeI3 layer and n-CsGeI3 layer on both sides of i-RbGeI3, which improved the energy level matching between i-RbGeI3 layer and the contact materials on both sides, and then facilitated the carrier transmission. We also added two interface defect layers (IDL) in order to be able to quantify the various adverse reactions at the interface, which reduces the recombination of carriers. We compared different electrode materials, and found that the appropriate metal work function can maximize the carrier transmission efficiency. We designed a structure of CsGeI3 instead of charge transport layer, and optimized the basic parameters of the battery with SCAPS. Reasonable thickness display can not only improve the absorption rate of photons, but also significantly reduce the recombination rate. Excessive trapping density increases electron/hole recombination, which is not conducive to carrier transportation. The appropriate band gap improves the matching degree of energy levels of each layer, and then promotes the transport of carriers between interfaces. At high temperature, more strain is generated inside the battery, which causes the crystal structure of the battery to deform. The high doping concentration strengthens the internal potential and promotes the carrier migration. The efficiency of the battery reached 34.96%, and the efficiency of other batteries with the same structure was less than 20%. Our research proved the great potential of doping CsGeI3 to construct all perovskite solar cell structures.

Design and efficiency enhancing of a new perovskite solar cell through a finite element model: A 3D computational study

With considerable advancements in perovskite materials, there is a growing need for computational models to design and analyze perovskite solar cells (PSCs) before performing experiments. Hence, in this work, a combined 3D optical–electrical model based on the finite element (FE) method is reported to fully characterize a designed structure of PSC. The endeavor behind this work is to use the developed FE model to obtain enhanced insights into the new PSC performance when using two perovskite materials as absorber layers. Firstly, since the mesh elements size significantly affects the convergence of a FE model, the mesh size was validated by reproducing previous experimental data. Results from the developed FE model were also compared to those of the Solar Cell Capacitance Simulator (SCAPS-1D) software in conjunction with the experimental data. Secondly, the developed FE model was performed to study the impact of using the eco-friendly Cs2AgGaBr6 double halide perovskite material as a second absorber layer in the new PSC structure. Thirdly, the influence of different parameters, such as the perovskite thickness, order of materials, and defect density, was thoroughly investigated using the developed FE model. Thus, we managed to predict an increase of the power conversion efficiency to 27.56%, which will require experimentation validation. Finally, the effect of several periodically corrugated back layers and various reflective metals was studied. The exploitation of the developed FE model would undoubtedly be fruitful as it used to fill the gap between the important number of the perovskite materials proposed in the literature on one side, and the lack of 3D computational model allowing the design and efficiency predicting of PSC prior to the experiment on the other side.

Study on effect of different HTL and ETL materials on the perovskite solar cell performance with TCAD simulator

Perovskite solar cell (PSC) has gained lots of attention in the scientific community because of achieving high efficiency in a short period of time. The basic structure of PSC is the active layer sandwiched between the electron transport layer (ETL) and hole transport layer (HTL). Overall device performance depends on the materials of ETL and HTL. This research studied the effect of different ETL and HTL materials and the variation of active layer thickness on the PSC performance with the Sentaurus TCAD simulator. For HTL and ETL, two types of materials were used: organic and inorganic. Organic HTL material was spiro-OMeTAD, inorganic HTL material was NiOx, Organic ETL was PCBM, and inorganic ETL was SnO2. It was observed that inorganic ETL and organic HTL showed the best result for the specific active layer thickness, and the best result was PCE of 21.61%, Voc of 1.23 V, Jsc of 19.31 mA/cm2 and FF of 90%.

Improving the Recombination Losses by the Inclusion of Bi‐HTM (CuO/Silicon) Layers for Formamidinium Tin‐Based Perovskite Solar Cells

AbstractThe innovative lead‐free formamidinium tin‐based perovskite solar cell structure is considered nontoxic and potentially more stable than lead‐based, although its performance is not yet excellent. This research aims to enhance the power conversion efficiency of perovskite solar cells and reduce the recombination losses. According to device modeling, the FASnI3 perovskite solar cell demonstrates a packing conversion efficiency of 14.3% (open circuit voltage (Voc) = 0.899 V, fill factor (FF) = 58.9%, and current density (Jsc) = 26.06 mA cm−2) by employing Bi hole transporting layers, a copper oxide, and crystalline silicon layers. Some features that affect the device include the thickness of each layer, the doping density of copper oxide and a silicon layer, and the back contact metalwork function. It is proposed that Bi‐HTL reduce the carriers to enter hole transport layer (HTL) as the doping change so that decreasing charge carriers recombination and enhancing the device efficiency in tin‐based perovskite solar cell with the structure of ITO/TiO2/FASnI3/CuO/Si/C. Furthermore, the impacts of various charge transport layers on energy band alignment, recombination, electric field, and IV properties are thoroughly explored.

Comparative Analysis of Perovskite Solar Cells for Obtaining a Higher Efficiency Using a Numerical Approach.

Perovskite materials have gained considerable attention in recent years for their potential to improve the efficiency of solar cells. This study focuses on optimizing the efficiency of perovskite solar cells (PSCs) by investigating the thickness of the methylammonium-free absorber layer in the device structure. In the study we used a SCAPS-1D simulator to analyze the performance of MASnI3 and CsPbI3-based PSCs under AM1.5 illumination. The simulation involved using Spiro-OMeTAD as a hole transport layer (HTL) and ZnO as the electron transport layer (ETL) in the PSC structure. The results indicate that optimizing the thickness of the absorber layer can significantly increase the efficiency of PSCs. The precise bandgap values of the materials were set to 1.3 eV and 1.7 eV. In the study we also investigated the maximum thicknesses of the HTL, MASnI3, CsPbI3, and the ETL for the device structures, which were determined to be 100 nm, 600 nm, 800 nm, and 100 nm, respectively. The improvement techniques used in this study resulted in a high power-conversion efficiency (PCE) of 22.86% due to a higher value of VOC for the CsPbI3-based PSC structure. The findings of this study demonstrate the potential of perovskite materials as absorber layers in solar cells. It also provides insights into improving the efficiency of PSCs, which is crucial for advancing the development of cost-effective and efficient solar energy systems. Overall, this study provides valuable information for the future development of more efficient solar cell technologies.

Lead-chelating hole-transport layers for efficient and stable perovskite minimodules

The defective bottom interfaces of perovskites and hole-transport layers (HTLs) limit the performance of p-i-n structure perovskite solar cells. We report that the addition of lead chelation molecules into HTLs can strongly interact with lead(II) ion (Pb2+), resulting in a reduced amorphous region in perovskites near HTLs and a passivated perovskite bottom surface. The minimodule with an aperture area of 26.9 square centimeters has a power conversion efficiency (PCE) of 21.8% (stabilized at 21.1%) that is certified by the National Renewable Energy Laboratory (NREL), which corresponds to a minimal small-cell efficiency of 24.6% (stabilized 24.1%) throughout the module area. Small-area cells and large-area minimodules with lead chelation molecules in HTLs had a light soaking stability of 3010 and 2130 hours, respectively, at an efficiency loss of 10% from the initial value under 1-sun illumination and open-circuit voltage conditions.

Light absorption enhancement of perovskite solar cells by a modified anti-reflection layer with corrugated void-like nanostructure using finite difference time domain methods

Perovskite solar cells (PSC) have become a growing research interest due to their flexibility, attractive properties, and low production cost. However, the thin-film structure of PSC often results in a not fully absorbed incident light by the active layer, which is crucial to determine PSC efficiency. Thus, the fabrication of an active layer with unique nanostructures is often used to enhance light absorption and general PSC efficiency. Using the theoretical simulation based-on Finite-Difference Time-Domain (FDTD) technique, this work demonstrates the successful improvement of light absorption by embedding corrugated void-like structure and perovskite thickness modification. The investigation of a corrugated void-type anti-reflection layer effect on light absorption is done by modifying the radius (r) and lattice constant (a) to obtain the optimum geometry. In addition, the MAPbI3 perovskite layer thickness is also adjusted to examine the optimum light absorption within the visible length to near-infrared. The theoretical calculations show that the optimum r = 692 nm and a = 776 nm. Meanwhile, the optimum absorber layer thickness is 750 nm. Compared to flat PSC, our proposed PSC absorbed more light, especially in the near-infrared region. Our result shows demonstrates the successful enhancement of light absorption by embedding corrugated void-like structure and modifying the perovskite thickness using a theoretical simulation based on the FDTD technique.

Achieving high-efficiency perovskite-based solar cells through engineering hole-transport layer

Perovskite solar cells (PSCs) based on Quantum dot hole transporting layers (QD-HTLs) have been widely studied recently. However, although the QD-HTLs have proved their potential in PSCs, it remains a big challenge to enhance the hole mobilities of QD-HTLs while maintaining their stability. Based on the extracted results of this research, we demonstrate that introducing CuInS2 QDs as HTMs result in remarkably improved performance of PSCs. After improving the preparation process, QD interlayers are provided with a high-quality perovskite thin film by passivating the perovskite surface. The perovskite film has 16.34 nm surface roughness which is low, and it obviously has clear grain boundaries. For fabricated PSCs, the Photoelectric conversion efficiency (PCE) is remarkably enhanced so that its value increased from 3.25% to 14.22%. Consequently, CuInS2 QDs are utilized at an optimum concentration along with superficial ligands as hole transport materials, which control the shape and the size of the CuInS2s and shows favourable effects on the performance of the perovskite-based solar cell. We also study the CuInS2 QD/perovskite interface in order to consider the carrier dynamic transportation behaviour, in which the results are increasing the photobleaching recovery rate and quenching the fluorescence. Finally, we demonstrate that for fabricating PSCs, the CuInS2 QDs are one of the most promising inorganic QDs with a role of HTMs in the structure of PSCs.