Assessment of Lead‐Free Tin Halide Perovskite Solar Cells Using J–V Hysteresis

Abstract

Perovskite solar cells (PSCs) are considered as one of the most promising alternatives for existing solar cells due to its excellent optoelectronic properties and high efficiency. However, lead has posed a serious issue due to its toxicity which may hinder the commercial use of lead‐based perovskite solar panels/arrays. There has been substantial work progress to find an environment‐friendly alternative metal ion to replace lead. Tin (Sn)‐based PSCs have been successfully synthesized and optimized with high efficiency, making it the most promising active material for lead‐free PSCs. In this review, the role of J–V hysteresis in tin halide PSCs is discussed from the perspective of system structure, working concepts, and interfacial carrier dynamics in detail. The problem of hysteresis in PSCs is closely linked to ion migration, ferroelectric effects, capacitive effects, and trap‐assisted recombination processes, which are highlighted in this review. Further, remediation to reduce the hysteresis by various strategies is explained for tin‐based perovskites. The core focus of this review is to analyze the deterioration of device performance and stability caused due to the generation of defects in the perovskite films, leading to a time‐dependent hysteresis of the current–voltage curves.

Challenges and strategies toward long-term stability of lead-free tin-based perovskite solar cells

“…The losses in the performance in Sn-HPSCs still arise even when ruling out external sources of degradation. These reactions are due to the intrinsic characteristics of the device and the constituent materials, such as carrier trapping-detrapping, grain boundaries, the polarisation of the metallic electrodes, ion migration in the photoactive layer, the ferroelectric effect of the photoactive layer, and halide segregation in mixed halide systems [106][107][108][109][110] .…”

“…However, as simple as it may seem, changes in the scan conditions (i.e., scan rate, scan speed, etc) during the measurement generate hysteresis of different magnitudes in the J-V curve, being this still a matter of concern when comparing the efficiencies reported in the literature. In fact, the main causes for the observation of hysteresis are due to the materials forming the device, such as the phase discontinuity of the photoactive film, inactivation caused by defects, the kinetics in the extraction of charge carriers at the interface, and the quality of the photoactive layer 106,111 . But despite the influence of the materials, the scan specifications are at the end critical parameters to determine the PCE of the devices.…”

Solution-processed next generation thin film solar cells for indoor light applications

“…The use of toxic lead as a major component for the absorber of high-performing PSCs raises concerns about using perovskite materials in indoor environments. 179 Significant research is going on to realize leadfree perovskite absorber materials for high-performing PSCs with enhanced stability. 180,181 Perovskite solar cells have presented high PCEs tested under 1 sun illumination in many reports.…”

Sn‐Based Perovskite Halides for Electronic Devices

“…TPSC fabricated with the p-i-n structure exhibits less hysteresis, high PCE, and light soaking stability due to the shorter diffusion length and higher charge mobility of the THP film. [48,118,143] In the p-i-n structure of TPSCs, the THP layer is fabricated on top of an HTL layer. Generally, poly(3,4-ethylenedioxythiophene (PEDOT:PSS) [144] is applied as an HTL layer with a VB level of −5.20 eV, which matches well with the VB of that THP layer.…”