Lead-free Perovskite Solar Cells Research Articles

Modeling and performance investigation of novel inorganic Cs4CuSb2Cl12 nanocrystal perovskite solar cell using SCAPS-1D

For the next generation of photovoltaic devices, perovskite solar cells (PSCs) appear as a good choice because they are simple and convert energy to electricity very efficiently. Recent years have seen a great deal of interest in organic-inorganic lead halide perovskites due to their exceptional optoelectronic properties. Nonetheless, additional commercialization of the Pb element is still restricted by its inevitable toxicity. To address the instability and toxicity of the lead hybrid perovskite, it is imperative to produce entirely inorganic lead-free perovskite nanocrystals. Cs4CuSb2Cl12 offers promising qualities and strong stability against light, heat, and humidity to overcome these drawbacks. It possesses an efficient photo-generated carrier and good carrier mobility. In this study, a lead-free perovskite solar cell with the novel configuration of FTO/WS2/Cs4CuSb2Cl12/CuSbS2/Ni has been optimized using SCAPS-1D simulation software and investigates the potential of Cs4CuSb2Cl12 nanocrystal solar cell. The impact of different characteristics of charge transport materials on Cs4CuSb2Cl12 nanocrystal solar cells has been reported. Additionally, the study computationally optimizes the thickness of perovskite layer, doping concentration, defect density, and other input parameters to propose an effective PSC with power conversion efficiency of 23.10 %, Voc of 1.1675V, and FF of 83.33 %.

Restraining Photocurrent Loss of Lead-Free Perovskite Solar Cells by Regulating Surficial Hydroxyl of Fluorine-Doped Tin Oxide

Restraining Photocurrent Loss of Lead-Free Perovskite Solar Cells by Regulating Surficial Hydroxyl of Fluorine-Doped Tin Oxide

Exploring the potential applications of lead-free organic–inorganic perovskite type [NH3(CH2)nNH3]MCl4 (n = 2, 3, 4, 5, and 6; M = Mn, Co, Cu, Zn, and Cd) crystals

The organic–inorganic hybrid perovskite compounds have been extensively studied since the dawn of a new era in the field of photovoltaic applications. Up to now, perovskites have proven to be the most promising in terms of power conversion efficiency; however, their main disadvantages for use in solar cells are toxicity and chemical instability. Therefore, it is essential to develop a hybrid perovskite that can be replaced with lead-free materials. This review focuses on the possibility of applying lead-free organic–inorganic perovskite types [NH3(CH2)nNH3]MCl4 (n = 2, 3, 4, 5, and 6; M = Mn, Co, Cu, Zn, and Cd) crystals. We are seeking organic–inorganic hybrid perovskite materials with very high temperature stability or without phase transition temperature, and thermal stability. Thus, by considering the characteristics according to the methylene lengths and the various transition metals, we aim to identify improved materials meeting the criteria mentioned above. Consequently, the physicochemical properties of organic–inorganic hybrid perovskite [NH3(CH2)nNH3]MCl4 regarding the effects of various transition metal ions of the anion and the methylene lengths of the cation are expected to promote the development and application of lead-free hybrid perovskite solar cells.

Improving Hybrid Tin Halide Films by Tin Trifluoromethanesulfonate for Lead-Free Perovskite Solar Cells.

Tin-based perovskite solar cells (Sn-PSCs) without toxic lead ions outperform other types of lead-free PSCs in terms of photovoltaic performance. To avoid the oxidation of Sn2+ cations and the formation of vacancy defects, most reports involve the addition of SnF2 to the perovskite precursor solution, but hybrid tin halide (Sn-PVK) films still suffer from poor crystallinity and stability. In this work, we used an alternative additive of tin trifluoromethanesulfonate (Sn(OTF)2). Compared to SnF2, the solubility of Sn(OTF)2 in the precursor solution is greatly improved, and the crystal nucleation process is delayed, resulting in the enhancement of crystal growth. The coordination ability of the OTF- anions suppresses the oxidation of Sn2+ cations, which promotes the stability of Sn-PVK films. By replacing the conventional additive of SnF2 with Sn(OTF)2, the device achieves an increase in power conversion efficiency from 7.96% to 10.3%, while the stability of the devices is improved simultaneously.

Highly efficient, low-cost, lead-free bifacial perovskite solar cells: A designing strategy through simulation

The bipolar properties of perovskites make it fascinating to design a perovskite solar cell (PSC) without a hole transport layer (HTL). An HTL-free PSCs provide easy fabrication, are low-cost, and time-saving. In HTL-free PSCs, the crystallinity and morphology of perovskite film can enhance device performance. With the bifacial approach, the device efficiency can be further enhanced. In the present work, HTL-free bifacial PSCs have been simulated, and a strategy has been provided to design a high-performance device. In investigating the effect of various electron transport layers (ETLs) and lead-free perovskite layers, we observed that a suitable combination of ETL and perovskite is vital to achieve a higher power conversion efficiency (PCE). The Mott-Schottky analysis of ETL/perovskite interfaces reveals that the built-in potential depends on the bandgap of the perovskite absorber layer, which affects the device performance by setting up higher open circuit voltage (VOC). A higher dielectric material between the ETL and the perovskite layer improves the device performance. Additionally, lowering the doping density of the perovskite layer increases the bifacial factor of the device. While optimizing our cells, the champion device with configuration FTO/Zn2SnO4/MASnI3/UT-Au (ultra-thin gold) exhibits a PCE of 19.76 % and 15.97 % for the front and rear illumination, respectively. By replacing UT-Au with MAM(MoOx/Ag/MoOx) transparent conducting triple-layer electrode, our device shows an improved PCE of >25 % for both front and rear illumination. The outcomes of these studies are anticipated to be beneficial in designing and optimizing HTL-free bifacial PSCs in the experiment.

Analysis and optimization of lead-free perovskite solar cells: investigating performance and electrical characteristics

AbstractSeveral studies on solar cells using SCAPS-1D were conducted to investigate their performance, which are typically limited to I–V analysis for DC characterization. Therefore, in the present study, a very wide frequency range from 10–2 Hz to 1012 Hz was employed to explore diffusion processes and investigate the performance of lead-free Perovskite Solar Cells (PSCs) featuring as a novel heterostructure. These investigations concern the optimization of MASnI3 thickness as an absorber. Additionally, the impact of series (Rs) and shunt (Rsh) resistances is also examined. From the I–V analysis, it was determined that the power efficiency (PCE) could be achieved at a thickness of 0.6 µm. Increasing the series resistance (Rs) led to a significant decrease in the fill factor (FF) and (PCE), whereas the shunt resistance (Rsh) demonstrated a notable improvement in both (FF) and (PCE). Analysis of AC characteristics revealed complex impedance (Z*) and modulus (M*) indicative of main ionic transport, recombination, and diffusion processes crucial for optimization. An appropriate equivalent circuit model was developed and validated through deconvolution and theoretical considerations, yielding parameters such as the time constant for each process. It was observed that ionic conductivity and electronic diffusion play key roles in balancing charge collection and recombination losses. The critical influence of series and shunt resistance on low and high-frequency processes was emphasized, underscoring their significance in solar cell efficiency. A strong correlation was established between the evolution of time constants for each process and power conversion efficiency (PCE).

Replacing the electron-hole transport layer with doping: SCAPS simulation of lead-free germanium-based perovskite solar cells based on CsGeI3

In recent years, scientists have shown increasing interest in perovskite solar cells because of their remarkable light absorption capabilities and promising prospects, among which germanium-based perovskite solar cells have been praised for non-toxicity. However, the defects between the charge transport layers affect its performance, and the charge transport layer materials also bring environmental hazards due to some organic properties. In this work, we propose to replace the charge transport layer with a solar cell based entirely on the germanium-based perovskite absorption layer by varying the CsGeI3 doping concentration. We created n-CsGeI3 and p-CsGeI3 layers conducive to electron hole transport, thus effectively reducing the defects between the interface transport layers, improving the electron hole transport environment, and improving the transmission efficiency. We employed SCAPS software for designing and optimizing the cell structure, enabling us to model and fine-tune parameters such as band gap, thickness, doping concentration, and defect density. These optimizations led to the calculation of optimal values, resulting in an impressive 34.57 % efficiency. The cell structure developed in this work validates the feasibility of germanium-based perovskite solar cells without electron hole transport layer, reducing environmental risks and optimizing performance parameters to some extent. This provides a valuable reference for future research on such solar cells.

Unraveling the Role of 2D Ti3C2Tx MXene Nanosheets in Cu-Based Double Perovskite Active Layer for Enhanced Photovoltaic Performance.

Although the atmospheric stability of lead-free inorganic double perovskite (DP) solar cells (PSCs) looks promising, their further development is hampered by inadequate film quality and non-radiative carrier recombination at the interfaces. Herein, the incorporation of a newly developed intriguing class of 2D material Ti3C2Tx MXene nanosheets with the photo-absorbing Cu2AgBiI6 (CABI) active layer of a fully inorganic solar cell is reported. The highly conductive Ti3C2Tx nanosheets work as a multi-functional additive by tuning the band gap, reducing the non-radiative carrier recombination, and inhibiting carrier accumulation. In addition, the presence of Ti3C2Tx MXene increases the surface free energy of the perovskite film, which elevates the energy barrier for nucleation and realizes a highly crystalline CABI perovskite film. Primarily, the MXene modification accelerates the charge extraction and transport at the interfaces of the active layer, utilizing energy level alignment with the charge transport layers. Consequently, the photo-conversion efficiency (PCE) of the device with MXene is substantially enhanced to 1.50%. Moreover, the 2D Ti3C2Tx nanosheets increased the long-term stability of the devices by retaining 70% of the initial PCE after 1680 h. With regard to relieving the severe carrier recombination at the interfaces, this work sets a new paradigm toward imminent solar energy conversion.

Optimization of Lead-Free Cs2TiBr6 Green Perovskite Solar Cell for Future Renewable Energy Applications

Optimization of Lead-Free Cs2TiBr6 Green Perovskite Solar Cell for Future Renewable Energy Applications

Studies on the performance of FASnI3:Zn2+-based lead-free perovskite solar cells: A numerical simulation

The search of stable, lead-free absorber material for perovskite solar cells (PSC) resulted in many alternatives, particularly, zinc (Zn) doped formamidinium tin iodide (FASnI3). This work facilitates in investigating the behavior of four different Zn doping ratios 0 %, 2 %, 5 %, and 10 % (say Zn-0, Zn-2, Zn-5, and Zn-10) on the performance of FTO/PCBM/FASnI3:Zn2+/MoOx/Au solar cell structure. A precise evaluation on the impact of the four various Zn doping ratios in the mentioned solar structure in terms of thickness of perovskite absorber layer, hole transport layer, and electron transport layer were executed. The investigation through numerical study further deals with the role of interfacial defect density and capture cross-section of charge carriers on the performance of suggested PSCs with varying Zn doping ratios. It is evident from the optimization results that PSC having absorber layer thickness of 400 nm yields better power conversion efficiency (PCE) of 11.49 % for Zn-5. The PCE is further improved to 13.98 % for capture cross section of 2 ×10−15 cm2. The entire work witnessed distinguishable superior behavior from FASnI3-based PSC doped with Zn ratio: Zn-5 in comparison to the PSCs doped with other Zn ratios. Furthermore, impact of the series and shunt resistances on performance parameters are also examined.

Perovskite materials with improved stability and environmental friendliness for photovoltaics

Finding innovative, stable, and environmentally acceptable perovskite (PVK) sunlit absorber constituents has developed a major area of study in photovoltaics (PVs). As an alternative to lead-based organic-inorganic halide PVKs, these PVKs are being researched for use in cutting-edge PVK solar cells. While there has been progress in this field as of late, there are still several scientific and technical questions that have yet to be answered. Here, we offer insights into the big picture of PVK toxicity/instability research, and then we discuss methods for creating stable, non-toxic PVKs from scratch. It is also believed that the processing of the proposed PVKs, which occurs between materials design and actual devices, poses novel challenges. PVK PVs that are both stable and ecologically benign can be created if these topics receive more attention. It is interesting to note that although perovskite solar cells (PSCs) have impressive power conversion efficiency, their commercial adoption is hindered by lead toxicity. Lead is a hazardous material that can cause harm to humans and the environment. As a result, researchers worldwide are exploring non-toxic lead-free photovoltaics (PSCs) for a sustainable and safe environment. To achieve this goal, lead in PSCs is replaced by non-toxic or less harmful metals such as tin, germanium, titanium, silver, bismuth, and copper. A study has been conducted that provides information on the characteristics, sustainability, and obstacles of replacing lead with these metals in PSCs. The paper also explores solutions for stability and efficiency issues in lead-free, non-toxic PSC commercialization, including altering manufacturing techniques and adding additives. Lastly, it covers the latest developments/future perspectives in lead-free perovskite solar cells that can be implemented in lead-free PSCs.

A hot phonon bottleneck observed upon incorporation of SnF2 to MASnI3 films and its possible role in increasing photocarrier diffusion length

While SnF2 is reported as an effective additive for improving the efficiency of lead-free tin-based perovskite solar cells, the mechanism is still unclear and requires further studies. Upon incorporating SnF2 into MASnI3, SnF2 reduces the intrinsic carrier density from 1018 to 1012 cm–3 and produces a longer carrier diffusion length as confirmed by the Hall measurements. The femtosecond transient absorption spectroscopy shows that SnF2 doping enhances the hot-phonon bottleneck effect of MASnI3. The slow cooling process of hot carriers may help to reduce non-radiative recombination, increase the fluorescence lifetime, and, therefore, improve the utilization rate of carriers. Finally, lead-free low bandgap perovskite MASnI3 is utilized as a light absorbing layer in solar cells, achieving high optical current and high voltage in tin-based perovskite solar cells. The final power conversion efficiency is 10.2%, while the power conversion efficiency for the control unit is 6.69%.

Spin-coated high mobility MoO3 thin film for designing highly efficient lead-free perovskite solar cells

Among the thin film-photovoltaics, perovskite solar cells (PSCs) are one of the most developing topics of research in recent times. Research records reveal that around 26 % efficiency in PSCs has already been achieved so far. However, the commercialization of those PSCs is hindered due to the toxicity of lead (Pb), and the instability of organic cations as well as structural volatility. Several inorganic materials including inorganic hole transport layer (HTL) have recently been proposed and developed to reduce the organic part in the device structure. We fabricate MoO3 thin film materials and conduct a detailed study to realize the potential of MoO3 as a unique HTL for application in PSCs. The synthesis of MoO3 thin film includes several characterization techniques e.g. XRD, FESEM, EDX, UV–Vis, and Hall Effect measurement. We design a MoO3 thin film-based, lead-free PSC structure of FTO/MoO3/PTAA/(FA)2BiCuI6/ZnO/Ag and perform numerical analysis using the SCAPS-1D simulation tool. In the device simulation process, we use the experimentally obtained optoelectrical properties of the MoO3 film and achieve a maximum efficiency of around 22.28 % in a contained lead-free PSC.

Performance optimization of MASnI3 perovskite solar cells: Insights into device architecture

Recent research has focused an extensive amount of attention on the lead-free substance lead-free methylammonium tin(Sn) tri-iodide (MASnI3), which has emerged as a highly potential absorber layer in the structure of the device. Because it has a larger visible absorption spectrum and a shorter band gap of 1.3 eV than the lead halide perovskite, MASnI3 is a potential alternative to MAPbX3. Through numerical simulation, the different parameters on the device performances are fully investigated. We achieved an open-circuit voltage (Voc) of 0.93 V, a short-circuit current density (Jsc) of 22.20 mA/cm2, a fill factor (FF) of 78.81 %, and a power conversion efficiency (PCE) of 16.39 % using the optimised conditions. It demonstrates the huge potential of recently created lead-free perovskite solar cells and opens up a large dimension of opportunities for the creation of novel perovskite solar cells with a variety of photovoltaic applications. The amalgamation of the Tungsten Disulfide (WS2) material layer between the electron transport layer (ETL) and the absorber layer raised the device module's power conversion efficiency to 20.36 %.

Rubidium based new lead free high performance perovskite solar cells with SnS2 as an electron transport layer

Lead-free perovskite-based solar cells has acquired rapid and expanding attention due to removing hazardous lead from perovskite materials. The major goal of this work is to supplement the research progress by doing a comparative analysis of lead-free perovskite-based solar cells using DFT and a numerical simulation method with the solar cell capacitance simulator-SCAPS-1D. At first, the bandgap and all optical performance were calculated via DFT then these data were applied SCAPS-1D simulator. Next design and optimized all solar cell performance parameters and compare of lead-free perovskite of RbSnCl3 and traditional perovskite RbPbBr3 solar cell with SnS2 as a high-bandgap chalcogenide electron transport layer (ETL) through SCAPS-1D. The effect of absorber and electron transport layer (ETL) thickness, doping concentration, defect density, interface defect density and temperature impact on solar cell efficiency has been comprehensively explored and compared. The proposed heterostructure of Al/FTO/SnS2/(RbPbBr3 and RbSnCl3)/Au shows that the PCE over 29.75% and 33.61% obtained with VOC of 0.978 and 0.825 V, Jsc of 34.58 and 51.44 mAcm−2, and FF of 87.91 and 79.19% for RbPbBr3 and RbSnCl3 absorber, respectively. These detailed findings revealed that high-performance lead-free perovskite solar cells can be achieved in a near future.

High-Efficiency and Ultra-Stable Cesium-Bismuth-Based Lead-free Perovskite Solar Cells without Modification.

Perovskite solar cells (PSCs) have become a new photovoltaic technology with great commercial potential because of their excellent photovoltaic performance. However, the toxicity and poor environmental stability of Pb in Pb-based perovskites limit its large-scale application. Exploring alternatives to Pb is an available approach to develop environmentally friendly PSCs. As an adjacent element of Pb, Bi shows many similar physical and chemical properties; therefore, it is commonly applied for B site substitution in Pb-based PSCs. CsBiSCl2, a new Pb-free perovskite system, was synthesized for the first time as a light absorber. By preparing DMABiS2 as an intermediate, Cs-Bi-based CsBiSCl2 perovskite films with a band gap over 2.012 eV were prepared by introducing CsCl, and the optimal annealing temperature, time, and stoichiometric ratio of the film were explored in this work. The conventional structure of CsBiSCl2 PSCs achieved a power conversion efficiency (PCE) of 10.38%, and the efficiency declined by only 3% after aging in air for 150 days, showing excellent stability, which is one of the most stable devices in inorganic PSCs. This work opens up a new road for the future development of environmentally friendly and commercially stable lead-free PSCs.

Design and optimization of high-performance eco-friendly perovskite solar cells: Utilizing FAMASnGeI3 and CsGeI3 as absorbers and tuning HTL and interface parameters

In this work, several designs of lead-based and lead-free perovskite solar cells (PSCs) have been developed and investigated. For the proposed designs, CH3NH3PbI3 (lead-based), FAMASnGeI3, and CsGeI3 (lead-free) are used as absorber materials, [Formula: see text] and NiO have been used as Hole Transport Layer (HTL) materials and TiO2 as Electron Transport Layer (ETL) materials. ETL materials, in general, have more concern with stability issues and HTL materials have more issues with efficiency improvements. The effect of changing thickness, doping density and defect density of the absorber layer, as well as HTL, defect density of absorber/HTL interface and work functions of front and back contacts on the performance of the proposed devices, are investigated. To enhance the device performance, optimization of the device parameters is performed. After optimization of different parameters, it is observed that the lead-based device structure TiO2/CH3NH3PbI3/NiO has a maximum efficiency of 29.94%. Even the corresponding lead-free device structure TiO2/CsGeI3/NiO exhibits a maximum efficiency of 29.19%. Additionally, this study delved into the influence of altering series and shunt resistances, as well as temperature on the operational characteristics of the lead-free optimized device. Such eco-friendly and cost-effective alternatives as lead-free perovskite cells can be very promising for future work.

High photovoltaic performance of lead-free Cs2AgInCl6-xBrx perovskite solar cell using DFT and SCAPS-1D simulations

The search of the lead-free highly efficient photovoltaic material is a key challenge for next generation solar cells. The structural, electronic, and optical properties of lead-free double perovskite Cs2AgInCl6-xBrx (x= 0,1,2,3,4,5 and 6) were investigated using density functional theory and its photovoltaic performance by using one-dimensional solar cell capacitance simulator SCAPS-1D. By increasing Br content in Cs2AgInCl6, the lattice parameter increases and the electronic band gap decreases without affecting the direct nature of band gap at Г- point. By mixing Br in Cs2AgInCl6 also provides an effective way to tune the energy band gap. In addition, increasing the Br content in mixed halide composition Cs2AgInCl6-xBrx (x= 0,1,2,3,4,5 and 6) reproduces more dispersive conduction band minima and valence band maxima result in lower effective masses of both charge carriers and consequently higher bipolar carrier mobility. The optical properties of Cs2AgInCl6-xBrx, such as absorption coefficient, reflectivity, dielectric constants, refractive index, and extinction coefficient were investigated with different Br concentrations. Among all compositions, the Cs2AgInClBr5 exhibits better optical properties and behaves as poor reflector and good absorber in the visible region. The photovoltaic performance of different absorber layers of Cs2AgInCl6-xBrx compositions in the perovskites solar cell module with configuration FTO/ETL/Cs2AgInCl6-xBrx /HTL/Au is analysed by using the SCAPS-1D. It is also observed that Cs2AgInClBr5 has high bipolar carrier mobility, relatively higher stability and direct band gap value of 1.75 eV with the PCE of 21.95% in the visible region indicate the suitability of the Cs2AgInClBr5 as a promising lead-free photovoltaic material.

Interface engineering and defect passivation for enhanced hole extraction, ion migration, and optimal charge dynamics in both lead-based and lead-free perovskite solar cells

The study elucidates the potential benefits of incorporating a BiI3 interfacial layer into perovskite solar cells (PSCs). Using MAPbI3 and MAGeI3 as active layers, complemented by the robust TiO2 and Spiro-OMeTAD as the charge-transport-layers, we employed the SCAPS-1D simulation tool for our investigations. Remarkably, the introduction of the BiI3 layer at the perovskite-HTL interface significantly enhanced hole extraction and effectively passivated defects. This approach minimized charge recombination and ion migration towards opposite electrodes, thus elevating device performance relative to conventional configurations. The efficiency witnessed a rise from 19.28 to 20.30% for MAPbI3 and from 11.90 to 15.57% for MAGeI3. Additionally, MAGeI3 based PSCs saw an improved fill-factor from 50.36 to 62.85%, and a better Jsc from 13.22 to 14.2 mA/cm2, signifying reduced recombination and improved charge extraction. The FF for MAPbI3 based PSCs saw a minor decline, while the Voc slightly ascended from 1.24 to 1.25 V and Jsc from 20.01 to 21.6 mA/cm2. A thorough evaluation of layer thickness, doping, and temperature further highlighted the critical role of the BiI3 layer for both perovskite variants. Our examination of bandgap alignments in devices with the BiI3 interfacial layer also offers valuable understanding into the mechanisms fueling the observed improvements.

Lead-free perovskite solar cell based on methyl ammonium tin iodide: Possible power conversion efficiency enhancement by device simulation

Although solar cells have the potential to create an endless amount of electrical power, their comparatively low power conversion efficiency draws the curiosity of both academics and industry. The primary goal of this research is to examine the performance of lead-free perovskite solar cells that use methyl ammonium tin iodide (CH3NH3SnI3) as the active material. The SCAPS-1D programme is employed for the simulation and analysis of the solar cells. The solar cell structure was analyzed computationally, and the resulting output was examined by comparing the I-V characteristic curves across different combinations of parameters. Various materials and combinations of parameters were explored in an effort to enhance the power conversion efficiency of solar cells based on CH3NH3SnI3. A series of comprehensive evaluations were undertaken to examine the influence of technical factors, including absorber layer thickness, defect density, and acceptor density, on performance. The acceptor density that yielded the best results was selected in order to improve the performance of the solar cell. The simulation results were acquired across a temperature range spanning from 300K to 450K, revealing enhanced stability within the range of typical ambient temperatures. The study produced encouraging findings, which included a short circuit current density of 30.81mA/cm2, an open circuit voltage of 1.25V, a fill factor of 80.35%, and a power conversion efficiency of 31.11%. This study has the potential to facilitate the development of environmentally sustainable, highly efficient, and cost-effective thin film solar cells based on CH3NH3SnI3, which exhibit noteworthy physical characteristics as alternatives to lead-containing perovskite solar cells.