Tin-based Perovskite Solar Cells Research Articles

Guanidine Thiocyanate‐Induced High‐Quality Perovskite Film for Efficient Tin‐Based Perovskite Solar Cells

Although tin‐based perovskite solar cells (TPSCs) are regarded as one of the most potential candidates in the field of lead‐free photovoltaics, the photoelectrical properties of TPSCs are limited because Sn2+ tends to be oxidized to be Sn4+ to produce tin vacancies, resulting in poor performance. Herein, guanidine thiocyanate (GASCN) is selected to regulate the quality of tin‐based perovskite film to fabricate efficient TPSCs. The device structure is ITO/PEDOT:PSS/PEA0.1FA0.9SnI3 with or without GASCN/PCBM/PEI/Ag. The effects of GASCN additive on the microstructure and photoelectrical properties of TPSCs are systematically investigated. The results show that the GASCN additive can form Lewis adducts with uncoordinated Sn atoms, inhibit the oxidation of Sn2+ to Sn4+, and passivate the trap states of perovskite films, resulting in the suppressed charge recombination and improved performance. Thus, the unsealed TPSCs with GASCN additive at the optimal process demonstrate a champion efficiency of 10.06% with better stability. Herein, an effective strategy to fabricate efficient and stable TPSCs is provided.

Synergistic Engineering of the Conductivity and Surface Properties of PEDOT:PSS-Based HTLs for Inverted Tin Perovskite Solar Cells to Achieve Efficiency over 10%

A new simple environmentally benign water-soluble zwitterion, sulfamic acid (SA), was used as a multifunctional additive to tune the properties of PEDOT:PSS-based hole transporting layer (HTL). A layer of PEDOT:PSS was inserted in-between the ITO electrode and SA-modified PEDOT:PSS to form a pseudo bi-layered PS/SA@PS HTL to protect the ITO electrode from damage by more acidic SA@PS. Inverted tin-based perovskite solar cells based on the pseudo bi-layered PS/SA@PS HTLs achieved the highest efficiency of 10.5% with very small current hysteresis. The cell lost only 5% of the initial efficiency by storing in a glovebox without packing for more than 2000 h. The functions of SA include increasing the conductivity and mobility of the HTL to extract and transport the hole facilely by changing the conformation of PEDOT chains via zwitterion-induced charge screening, elevating the work function of PEDOT:PSS to match the VB of TPsk via increasing the PSS- chains on the HTL surface, creating a more hydrophilic surface for depositing better quality tin perovskite film (TPsk with the chemical formula of FA0.98EDA0.01SnI3), and avoiding the oxidation Sn2+ to Sn4+via interacting with Sn2+ ions (at the HTL/absorber interface) using the sulfite group on SA, which were revealed with various physicochemical data.

Improving the performance of organic lead–tin laminated perovskite solar cells from the perspective of device simulation

The toxic lead in traditional perovskite solar cells (PSCs) poses a fatal threat to the environment, and it takes time and technology to complete the transition to lead-free perovskite solar cells. In this work, we introduce a lead–tin laminated perovskite solar cell, which can obviously reduce the toxicity of lead. Our ultimate goal is to study the factors that affect the performance of the device. On the basis of reducing the lead-based perovskite layer, use SACPS-1D (solar cell capacitor simulator) to optimize the parameters to maximize the performance of the entire device. Adjusting the physical parameters, we got the power conversion efficiency (PCE) of 17.59% and 6.14% for single-cell lead-based and single-cell tin-based perovskite solar cells respectively, which are close to the experimental results. The simulation results show that under the laminated structure, the thickness of the two perovskite absorber materials based on lead and tin has a certain influence on the performance of the device. After optimization, it is determined that the best thicknesses of lead-based absorption layer (LBA) and tin-based absorption layer (TBA) are 20 nm and 150 nm respectively. Optimize the doping concentration of acceptor and donor of the laminated perovskite absorber layer to obtain higher PCE and open circuit voltage (VOC). The best values are 1015 cm−3 and 1016 cm−3 for LBA and TBA respectively. We also found that when adjusting the positions of LBA and TBA, the recombination rate under different defect densities verified that the laminated absorption layer close to the light source side dominates the device performance. Provide reference for future optimization of laminated perovskite solar cells. Considering these factors comprehensively, we optimized the device performance parameters as follows: VOC = 0.93 V, JSC = 19.56 mA/cm2, FF = 71.12% and PCE = 12.89%.

Preparation of tin-based perovskite solar cell thin films assisted by stannous fluoride

While the conversion efficiency is constantly refreshing, perovskite solar cells are also actively moving towards the goal of commercial application. However, its structure contains Pb, a toxic substance, which violates the original intention of energy saving and environmental protection of solar cells and hinders the development of its commercialization. The purpose of this paper is to improve the device performance of environment-friendly lead-free tin-based perovskite solar cells. In this paper, SnF2 is firstly precipitated in perovskite solution and used as heterogeneous nucleation point, which helps tin-based perovskite precipitate faster and more uniformly, and then grows into a flat and compact film after annealing. With the increase of x, the lattice shrinkage of perovskite becomes more obvious, and the unit cell size of the film surface becomes larger. When x increases from 0 to 0.5, the energy conversion efficiency of the same batch of devices reaches 1.803% and VOC is 0.3283 V when x=0.5 is used. Low dimensional tin-based perovskite is formed by doping phenylethylamine into FASnI3 structure, and perovskite thin films are prepared by one-step method with different anti-solvent spin coating, which improves the device performance and greatly improves the stability of solar cells.

Fullerene Derivative with Flexible Alkyl Chain for Efficient Tin-Based Perovskite Solar Cells.

Fullerene derivatives are considered excellent materials for the extraction and transportation of electrons in the production of efficient tin-based perovskite solar cells (TPSCs). However, it is not clear how the molecular structure of fullerene derivatives affects the efficiency and stability of TPSCs. In this study, the effects of fullerene derivatives, (6,6)-phenyl-C61-butyric acid hexyl ester (PCBH) and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM), with different functional groups, on photovoltaic performance were investigated. The flexible alkyl chain of PCBH effectively improved the film morphology and stability, the electron extraction and transport capabilities, and the interface contact of fullerene and perovskite. As a result, the PCBH-based TPSC yielded a higher efficiency, of 9.21%, than the PCBM-based devices (7.54%). More importantly, the PCBH-based films exhibited higher stability and effectively suppressed the oxidation of Sn2+ by inhibiting oxygen permeation. Therefore, the PCBH-based devices exhibited significantly enhanced stability. This result indicates that optimizing the functional group of fullerene derivatives is crucial for improving the efficiency and stability of TPSCs.

Optimization of Absorber and ETM Layer Thickness for Enhanced Tin based Perovskite Solar Cell Performance using SCAPS-1D Software

The methyl ammonium tin iodide (〖CH〗_3 〖NH〗_3 〖SnI〗_3) perovskite nanocrystals have attracted research interest and have become a rising star in the horizon of photovoltaics due to its narrow band gap, wide visible absorption coefficient and environmental friendliness than its lead-based counterpart (〖CH〗_3 〖NH〗_3 〖PbI〗_3). In this article, a tin based perovskite solar cell with Zinc oxide (ZnO) and Copper Oxide (CuO) as electron transport medium (ETM) and hole transport medium (HTM) was proposed and investigated numerically using a Solar Cell Capacitance Simulator (SCAPS) tool. With appropriate parameters, a short-circuit current density (Jsc) of 27.56 mA/cm^2, open-circuit voltage (Voc) of 0.82 V, fill factor (FF) of 59.32 %, and power conversion efficiency (PCE) of 13.41 % are obtained for the initial simulation. By varying the thicknesses of the absorber and electron transport layer, the optimum thicknesses were observed at 0.6 μm and 0.3 μm for 〖CH〗_3 〖NH〗_3 〖SnI〗_3 and ZnO with corresponding PCEs of 14.36 % and 13.42 %. Upon simulation with optimized parameters, a Jsc of 29.71 mA/cm^2, Voc of 0.83 V, FF of 61.23 % and PCE of 15.10 % were recorded. These values are superior to those obtained without optimization which means that solar cell performance can be improved to some extent by adjusting the perovskite and electron transport layer and also, 〖CH〗_3 〖NH〗_3 〖SnI〗_3 Perovskite solar cell (PSC) is a potential environmentally friendly solar cell with considerable efficiency.

A Numerical Simulation of Transport Layer Thickness Effect in Tin-Based Perovskite Solar Cell

This paper investigates the performance of a planar n-i-p perovskite solar cells (PSC) with lead-free perovskite absorber for three different metal oxides serving as the electron transport layer (ETL). A tin (Sn) based PSCs - with i) zinc oxide (ZnO), ii) titanium oxide (TiO2) and iii) tin oxide (SnO2) as the ETL, and spiro-MeOTAD as the hole transport layer (HTL) - are modeled and simulated using a 1-dimensional numerical software (SCAPS 1-D). Thicknesses of both the methylammonium tin iodide (CH3NH3SnI3) absorber and the ETL are varied for the purpose of achieving the optimum power conversion efficiency (PCE). For all metal oxide candidates, thickness of lead-free perovskite absorber layer is varied from 400 nm to 1500 nm. The obtained results show that the optimum recorded PCE is achieved at 900 nm. Moreover, the highest PCE value of 8.10% is observed for 80 nm thickness of SnO2 compared to 8.05% for ZnO and 7.99% for TiO2. Additionally, the results unveil that for a constant HTL thickness of 80 nm and ETL thickness increment up to 300 nm, the PCE is slightly reduced between 0.12% and 0.99% for all ETLs. We believe that this is the first simulation effort that evaluates the effect of transport layer thickness on the performance of lead-free PSC, hoping that the findings will be useful for the research community, particularly for those working in the field of solar cells fabrication and development.

Enabling water-free PEDOT as hole selective layer in lead-free tin perovskite solar cells.

Metal halide perovskites are set to revolutionise photovoltaic energy harvesting owing to an unmatched combination of high efficiency and low fabrication costs. However, to improve the sustainability of this technology, replacing lead with less toxic tin is highly desired. Tin halide perovskites are approaching 15% in power conversion efficiency (PCE), mainly employing PEDOT:PSS as a hole-selective layer. Unfortunately, PEDOT:PSS is processed from an aqueous solution, which is hardly compatible with the strict anoxic requirements for processing tin halide perovskites due to tin's instability to oxidation. Here, we present a water-free PEDOT formulation for developing tin-based lead-free perovskite solar cells. We show that the main difference between the PCE of devices made from aqueous and water-free PEDOT is due to the marked hydrophobicity of the latter, which complicates the perovskite deposition. By modifying the surface of water-free PEDOT with a thin Al2O3 interlayer, we could achieve good perovskite morphology that enabled perovskite solar cells with a PCE of 7.5%.

Synergistic effect of two hydrochlorides resulting in significantly enhanced performance of tin-based perovskite solar cells with 3D to quasi-2D structural transition

Hydrazine monohydrochloride (HMCl) inhibits Sn2+ oxidation, and diethylamine hydrochloride (DEACl) leads to a 2D structure. Under the synergistic effect of the two hydrochlorides, PCE and the VOC are largely enhanced for stable Sn-based devices.

Nucleation and crystallization manipulations of tin halide perovskites for highly efficient solar cells

Over recent years, the efficiency of tin-based perovskite solar cells (PSCs) has exceeded 14%, which indicates their significant potential in the photovoltaic field.

SCAPS simulated FASnI3 and MASnI3 based PSC solar cells: A comparison of device performance

In this paper, we have designed simulated, compare, and analyzed the high efficiency of FASnI3 and MASnI3 based PSC solar cell. In recent times, organic and inorganic Perovskite-based solar cells are turning to be hopeful devices due to their unique proprieties in the PV field. In our present work, we were concentrating several studies on Perovskite solar cell-based FASnI3 and MASnI3 Perovskite layer. Most of the Perovskite solar cell is made by Pb material for getting the high efficiency. However, the factor of toxicity and stability of the Pb-constructed devices is the main challenge to progress in commercial manufacture. In this study, numerical modeling of PSC used the alternative materials which are Sn-based Perovskite solar cells. In this work, we investigated tin-based perovskite solar cells with different absorber layers and also we investigated using high thickness in ETL and HTL what are change could be happen these are the things also we discussed in this paper. If we increase the thickness of the ETL and HTL the efficiency also increased we got some good results on it. Here we report simulation of lead-free Tin based PSC processed on FASnI3 and MASnI3 two different Perovskite layers. In our present work, we using 1D-SCAPS for numerical analysis.

Synergistic Trifluoroacetamide Regulating Crystal Orientation and Energy Alignment for Tin-Based Perovskite Solar Cells

Synergistic Trifluoroacetamide Regulating Crystal Orientation and Energy Alignment for Tin-Based Perovskite Solar Cells

Effect of acceptor density, thickness and temperature on device performance for tin-based perovskite solar cell

In the work, a perovskite solar cell is simulated in SCAPS-1D software using Methylammonium tin iodide (CH3NH3SnI3) as absorber, Titanium dioxide (TiO2) and Spiro-OMeTAD as electron and hole transport layers respectively. So as to obtain a high efficiency value along with a high fill factor, a detailed study of effect of several parameters that is absorber layer’s acceptor density, absorber layer’s thickness and solar cell’s operating temperature has been taken into account for thorough analysis. The optimized structure Spiro-OMeTAD/CH3NH3SnI3/TiO2/FTO achieves maximum output result at Fill factor (FF) 77.45%, Open circuit voltage (Voc) 0.89 V, efficiency (ɳ) 24.36% and short circuit current density (Jsc) 35.32 mA/cm2. Thus, a comparative study is done for different cell models.

Enhanced Photovoltaic Performance via a Bifunctional Additive in Tin-Based Perovskite Solar Cells

Tin-based perovskites with low toxicity and a narrow band gap have been promising candidates for the fabrication of efficient lead-free perovskite solar cells (PSCs). Nevertheless, the power conversion efficiency (PCE) of tin-based PSCs still lags behind that of their lead counterparts due to the poor film quality induced by uncontrollable crystal growth and Sn2+ self-doping. Herein, we introduce a bifunctional additive, ammonium thiocyanate (NH4SCN), into the precursor solution, which is able to coordinate with SnI2 to effectively control the crystal growth of the FASnI3 perovskite and further passivate the trap states in the perovskite films. Furthermore, the modified FASnI3 perovskite displays an improved film quality, featuring a compact surface morphology with an enlarged grain size, as well as decreased trap density, resulting in the reduction of the Sn4+/Sn2+ proportion in the film. As a result, a considerably enhanced PCE from 4.45 to 8.15% has been demonstrated. More importantly, the NH4SCN-based device exhibits advanced environment stability, retaining over 70% of the initial efficiency after 100 h of exposure to 35 ± 5% relative humidity at room temperature in a dark environment. This finding provides an additive strategy to improve the efficiency and stability of tin-based PSCs.

Substituted thiourea as versatile ligands for crystallization control and surface passivation of tin-based perovskite

Tin-based perovskite solar cells could replace their toxic, lead-containing counterparts and have been developed rapidly to exceed a power conversion efficiency (PCE) of 14%. However, further improvement is limited by poor film quality, largely because of fast crystallization and the tendency of tin-based perovskites toward defects. Here, we report that substituted thiourea can effectively slow the crystallization of formamidinium tin triiodide (FASnI3) and inhibit its surface defects. Thus, pinhole-free films comprising tiled FASnI3 crystallites are fabricated reproducibly. Annealed films retain a small percentage of the residual ligand, which can account for the observed carrier lifetimes of as long as 43 ns. By tuning the ligand structure, we progressively enhance the open-circuit voltage and short-circuit current density of our solar cells and attain PCEs of over 12%. Our simple solution simultaneously addresses two key issues of FASnI3 and paves the way for more efficient and robust tin-based perovskite solar cells.

Pseudohalide Functional Additives in Tin Halide Perovskite for Efficient and Stable Pb-Free Perovskite Solar Cells

The progress of tin-based halide perovskite solar cells (Sn-HaPSCs) is obstructed by their poor stability arising from tin oxidation. Herein, we introduced phenethylammonium thiocyanate (PEASCN) as...

The Voltage Loss in Tin Halide Perovskite Solar Cells: Origins and Perspectives

AbstractExploring stable and efficient lead‐free perovskite solar cells (PSCs) is critical to solving the environmental concerns caused by lead. Recently, tin halide perovskites (THPs) have become a promising candidate due to its low toxicity and similar electronic configuration to lead counterparts. Currently, the power conversion efficiency of tin‐based PSCs (TPSCs) has been pushed over 14%. However, there is still a considerable gap compared to lead PSCs due to the non‐negligible open‐circuit voltage loss (Vloss). Therefore, understanding the origins and regulation strategies of Vloss for TPSCs is of great importance. Herein, the nature of THPs is first reviewed from the crystal structure, electronic structure, and phase transition. Subsequently, the origins and determinants of Vloss are discussed in TPSCs. Besides the intrinsic low bandgap, the bulk recombination of tin perovskite, and the non‐radiative recombination of the associated interfaces induce the Vloss of the TPSCs devices. Then, some recently emerged strategies to suppress the Vloss in TPSCs are introduced. Finally, a perspective on the further suppression of Vloss in TPSCs including purifying the precursor solution, suppressing the oxidation Sn2+, and optimizing the device structure is outlined.

Diaminomaleonitrile Lewis Base Additive for Push–Pull Electron Extraction for Efficient and Stable Tin-Based Perovskite Solar Cells

Diaminomaleonitrile Lewis Base Additive for Push–Pull Electron Extraction for Efficient and Stable Tin-Based Perovskite Solar Cells

Tin-based perovskite solar cells: Further improve the performance of the electron transport layer-free structure by device simulation

With the rapid development of perovskite solar cells (PSCs), PSCs without electron transport layer (ETL) structure have been reported one after another, but the efficiency is low. In this work, a tin-based ETL-free structure of perovskite solar cell is introduced. In order to explore the internal influencing factors of the device with ETL-free structure, we used SCAPS-1D (Solar Cells Capacitance Simulator) to simulate the device and adjust the appropriate physical parameters to approximate the results reported in the experiment. The simulation results show that the thickness of the absorption layer, defect density, operating temperature and band gap have different effects on the performance of the device, and the best absorbent layer thickness is 600 nm. When the operating temperature exceeds 300 K, the performance parameters will decrease, and the band gap is best controlled at about 1.3 V. It should be pointed out that defect density is the main culprit that seriously affects device performance. When defect density exceeds 1015cm−3, power conversion efficiency (PCE) begins to decline significantly, and we need to pay more attention to defect density. At the same time, the effects of different interface defect layers (IDL) on device performance are simulated. It is found that when the defect density of the interface defect layer is too high, the asymmetry effect will appear. The interface defect layer IDL2 between the absorption layer and the hole transport layer (HTL) has a greater effect on the open circuit voltage (VOC), and the interface defect layer IDL1 has a greater effect on PCE. Therefore, it is necessary to pay attention to these defect layers to improve the VOC and PCE. Finally, based on ETL-free PSCs, we list HTL of different materials for reference, and provide new ideas for perovskite solar cells in the future.

Replacing the Electron-Hole Transport Layer by Doping: Optimization of Tin-Based Perovskite Solar Cells from a Simulation Perspective

Due to their non-toxic nature and good charge transport properties, tin-based perovskite solar cells are gaining attention. Here, we used SCAPS-1D (Solar Cell Capacitance Simulator) to simulate and analyze constructed devices. We then created n-MASnI3 and p-MASnI3 layers that facilitate electron-hole transport by changing the doping concentration of MASnI3 in the perovskite absorber layer, replacing the conventional electron transport layer (ETL) and hole transport layer (HTL). This simplifies the manufacturing process to reduce cost and realize the conversion of lead-free perovskite solar cells. By studying the thickness of n-MASnI3 and p-MASnI3, and the acceptor and donor doping concentrations (ND and NA), we explored the effects on each device performance parameter in terms of energy band distribution, recombination rate variation, and external quantum efficiency. The first optimization of the electron transport layer and hole transport layer was thereby achieved. A second optimized analysis of the doping concentration of i-MASnI3 absorber layer was achieved. Finally, we optimized the device performance parameters as V OC = 0.8827 V, J SC = 23.1720 mA cm−2, FF = 63.1390% and PCE = 12.9144%.