Advancement of Environment Friendly Emerging Lead-Free Perovskite Solar Cell Materials and Its Devices

In the advancement of photovoltaic (PV) technology, perovskite solar cells (PSCs) have proven potential in their evolution and have become vanguard research with an extraordinary power conversion efficiency (PCE) performance up to 26%, which stances a remarkable challenge to thin film and multi crystalline silicon (Si) photovoltaic technology. However, the toxicity of lead (Pb), stability issues etc., hampered the commercialization of perovskite solar cells. Scientists have made efforts for the development of different categories of lead-free perovskites, including tin halide perovskites, germanium-based perovskites, and heterovalent elements (Transition metal halide perovskite, double perovskites etc.). However, the performance of the corresponding devices is not up to the mark, and there are stability issues. The limitations mainly initiate from either the unstable lattice structure of these materials or their low dimensionality (e.g., structural and electronic dimensionality)-related to poor carrier transport and self-trapping effect, accelerating nonradiative recombination. This article reviews the environmentally friendly PSCs developed by the use of novel, low/nontoxic perovskite materials, with specific attention focused on assets of identical perovskites and pertinent production of high efficiency PV devices, notable achievement reports of all lead-free perovskites to date with PV performance, and stability of corresponding devices, photovoltaic applications and their commercialization.