Search Results (8)

Lead toxicity has hindered the wide applications of lead halide perovskites in optoelectronics and bioimaging. A significant amount of effort has been made to synthesize lead-free halide perovskites as alternatives to lead halide perovskites. In this work, we demonstrate the feasibility of synthesizing CsSnI₃-based powders mechanochemically with dual light emissions under ambient conditions from CsI and SnI₂ powders. The formed CsSnI₃-based powders are divided into CsSnI₃-dominated powders and CsSnI₃-contained powders. Under the excitation of ultraviolet light of 365 nm in wavelength, the CsSnI₃-dominated powders emit green light with a wavelength centered at 540 nm, and the CsSnI₃-contained powders emit orange light with a wavelength centered at 608 nm. Both the CsSnI₃-dominated and CsSnI₃-contained powders exhibit infrared emission with the peak emission wavelengths centered at 916 nm and 925 nm, respectively, under a laser of 785 nm in wavelength. From the absorbance spectra, we obtain bandgaps of 2.32 eV and 2.08 eV for the CsSnI₃-dominated and CsSnI₃-contained powders, respectively. The CsSnI₃-contained powders exhibit the characteristics of thermal quenching and photoelectrical response under white light. Full article

In this study, a novel systematic analysis was conducted to explore the impact of various parameters, including acceptor density (N_A), individual layer thickness, defect density, interface defect density, and the metal electrode work function, on efficiency within the FTO/ZnO/CsSnI₃/NiO_x/Au perovskite solar cell structure through the SCAPS-1D (Solar Cell Capacitance Simulator in 1 Dimension) simulation. ZnO served as the electron transport layer (ETL), CsSnI₃ as the perovskite absorption layer (PAL), and NiO_x as the hole transport layer (HTL), all contributing to the optimization of device performance. To achieve the optimal power conversion efficiency (PCE), we determined the ideal PAL acceptor density (N_A) to be 2 × 10¹⁹ cm⁻³ and the optimal thicknesses to be 20 nm for the ETL (ZnO), 700 nm for the PAL (CsSnI₃), and 10 nm for the HTL (NiO_x), with the metal electrode remaining as Au. As a result of the optimization process, efficiency increased from 11.89% to 23.84%. These results are expected to contribute to the performance enhancement of eco-friendly, lead-free inorganic hybrid solar cells with Sn-based perovskite as the PAL. Full article

By an abrupt rise in the power conservation efficiency (PCE) of perovskite solar cells (PSCs) within a short span of time, the instability and toxicity of lead were raised as major hurdles in the path toward their commercialization. The usage of an inorganic lead-free CsSnI₃-based halide perovskite offers the advantages of enhancing the stability and degradation resistance of devices, reducing the cost of devices, and minimizing the recombination of generated carriers. The simulated standard device using a 1D simulator like solar cell capacitance simulator (SCAPS) with Spiro-OMeTAD hole transporting layer (HTL) at perovskite thickness of 330 nm is in good agreement with the previous experimental result (12.96%). By changing the perovskite thickness and work operating temperature, the maximum efficiency of 18.15% is calculated for standard devices at a perovskite thickness of 800 nm. Then, the effects of replacement of Spiro-OMeTAD with other HTLs including Cu₂O, CuI, CuSCN, CuSbS₂, Cu₂ZnSnSe₄, CBTS, CuO, MoS₂, MoO_x, MoO₃, PTAA, P₃HT, and PEDOT:PSS on photovoltaic characteristics were calculated. The device with Cu₂ZnSnSe₄ hole transport in the same condition shows the highest efficiency of 21.63%. The back contact also changed by considering different metals such as Ag, Cu, Fe, C, Au, W, Ni, Pd, Pt, and Se. The outcomes provide valuable insights into the efficiency improvement of CsSnI₃-based PSCs by Spiro-OMeTAD substitution with other HTLs, and back-contact modification upon the comprehensive analysis of 120 devices with different configurations. Full article

Simplifying the design of lead-free perovskite solar cells (PSCs) has drawn a lot of interest due to their low manufacturing cost and relative non-toxic nature. Focus has been placed mostly on reducing the toxic lead element and eliminating the requirement for expensive hole transport materials (HTMs). However, in terms of power conversion efficiency (PCE), the PSCs using all charge transport materials surpass the environmentally beneficial HTM-free PSCs. The low PCEs of the lead-free HTM-free PSCs could be linked to poorer hole transport and extraction as well as lower light harvesting. In this context, a lead-free perovskite homojunction-based HTM-free PSC was investigated, and the performance was then assessed using a Solar Cell Capacitance Simulator (SCAPS). A two-step method was employed to fabricate lead-free perovskite homojunction-based HTM-free PSCs in order to validate the simulation results. The simulation results show that high hole mobility and a narrow band gap of cesium tin iodide (CsSnI₃) boosted the hole collection and absorption spectrum, respectively. Additionally, the homojunction’s built-in electric field, which was identified using SCAPS simulations, promoted the directed transport of the photo-induced charges, lowering carrier recombination losses. Homojunction-based HTM-free PSCs having a CsSnI₃ layer with a thickness of 100 nm, defect density of 10¹⁵ cm⁻³, and interface defect density of 10¹⁸ cm⁻³ were found to be capable of delivering high PCEs under a working temperature of 300 K. When compared to formamidinium tin iodide (FASnI₃)-based devices, the open-circuit voltage (V_oc), short-circuit density (J_sc), fill factor (FF), and PCE of FASnI₃/CsSnI₃ homojunction-based HTM-free PSCs were all improved from 0.66 to 0.78 V, 26.07 to 27.65 mA cm⁻², 76.37 to 79.74%, and 14.62 to 19.03%, respectively. In comparison to a FASnI₃-based device (PCE = 8.94%), an experimentally fabricated device using homojunction of FASnI₃/CsSnI₃ performs better with V_oc of 0.84 V, J_sc of 22.06 mA cm⁻², FF of 63.50%, and PCE of 11.77%. Moreover, FASnI₃/CsSnI₃-based PSC is more stable over time than its FASnI₃-based counterpart, preserving 89% of its initial PCE. These findings provide promising guidelines for developing highly efficient and environmentally friendly HTM-free PSCs based on perovskite homojunction. Full article

Recently, organic–inorganic perovskites have manifested great capacity to enhance the performance of photovoltaic systems, owing to their impressive optical and electronic properties. In this simulation survey, we employed the Solar Cell Capacitance Simulator (SCAPS-1D) to numerically analyze the effect of different hole transport layers (HTLs) (Spiro, CIS, and CsSnI₃) and perovskite active layers (ALs) (FAPbI₃, MAPbI₃, and CsPbI₃) on the solar cells’ performance with an assumed configuration of FTO/SnO₂/AL/HTL/Au. The influence of layer thickness, doping density, and defect density was studied. Then, we trained a machine learning (ML) model to perform predictions on the performance metrics of the solar cells. According to the SCAPS results, CsSnI₃ (as HTL) with a thickness of 220 nm, a defect density of 5 × 10¹⁷ cm⁻³, and a doping density of 5 × 10¹⁹ cm⁻³ yielded the highest power conversion efficiency (PCE) of 23.90%. In addition, a 530 nm-FAPbI₃ AL with a bandgap energy of 1.51 eV and a defect density of 10¹⁴ cm⁻³ was more favorable than MAPbI₃ (1.55 eV) and CsPbI₃ (1.73 eV) to attain a PCE of >24%. ML predicted the performance matrices of the investigated solar cells with ~75% accuracy. Therefore, the FTO/SnO₂/FAPbI₃/CsSnI₃/Au structure would be suitable for experimental studies to fabricate high-performance photovoltaic devices. Full article

Over the past decade, organic–inorganic hybrid perovskite solar cells (PVSCs) have shown unprecedented growth in power conversion efficiency (PCE) from 3.8% to 25.7%. However, intrinsic thermal instability and lead toxicity are obstacles limiting its large–scale commercialization. Thus, all-inorganic CsSnI₃ perovskite has drawn remarkable interest owing to its nontoxicity, excellent thermal stability, low-cost fabrication, and spectacular photoelectric characteristics, including ideal bandgap range, long carrier lifetime, and large absorption coefficient. Many studies have shown that the device performances are closely related to the morphology and crystallinity of perovskite films. In this review, the physical properties of CsSnI₃ perovskite are summarized. Furthermore, this review primarily narrates the recent progress in optimizing the morphology by various strategies such as additive engineering, composition regulation, and deposition techniques, emphasizing their effects on grain sizes, film uniformity, grain boundary, and defect passivation. Full article

Perovskite solar cells have become the current research focus because of their high conversion efficiency and other advantages; however, the toxicity of lead used in them has raised environmental concerns. Tin-based perovskite materials have become the most promising alternative materials for perovskite solar cells because of their relatively low toxicity, suitable band gap and relatively higher energy conversion efficiency than perovskite materials based on other elements. In this article, the status of this rapidly growing field, authors’ output and cooperation, hot research topics, important references and the development trends of tin-based perovskite solar cells are identified and visualized using CiteSpace software. The main research fields are found to be optical properties, 3D–2D perovskite and perovskite solar cell conduction band materials. The mixed organic metal halide perovskite solar cell and the CsSnI₃ semiconductor are identified as emerging trends for tin-based perovskite solar cells. Such contents in this article highlight the key points in the wide field of literature so it can be understood efficiently. Full article

Tin-based halide perovskite compounds have attracted enormous interest as effective replacements for the conventional lead halide perovskite solar cells (PCSs). However, achieving high efficiency for tin-based perovskite solar cells is still challenging. Herein, we introduced copper sulfide (CuS) as a hole transport material (HTM) in lead free tin-based B-γ-CsSnI₃ PSCs to enhance the photovoltaic (PV) performances. The lead free tin-based CsSnI₃ perovskite solar cell structure consisting of CuS/CsSnI₃/TiO₂/ITO was modeled and the output characteristics were investigated by using the one dimensional solar cell capacitance simulator (SCAPS-1D). The CuS hole transport layer (HTL) with proper band arrangement may notably minimize the recombination of the charge carrier at the back side of the perovskite absorber. Density functional theory (DFT)-extracted physical parameters including the band gap and absorption spectrum of CuS were used in the SCAPS-1D program to analyze the characteristics of the proposed PV device. The PV performance parameters of the proposed device were numerically evaluated by varying the absorber thickness and doping concentration. In this work, the variation of the functional temperature on the cell outputs was also studied. Furthermore, different HTMs were employed to investigate the PV characteristics of the proposed CsSnI₃ PSC. The power conversion efficiency (PCE) of ~29% was achieved with open circuit voltage (V_oc) of 0.99 V, a fill factor of ~87%, and short circuit current density (J_sc) of 33.5 mA/cm² for the optimized device. This work addressed guidelines and introduced a convenient approach to design and fabricate highly efficient, inexpensive, and stable lead free tin-based perovskite solar cells. Full article