Optimization based on computational analysis of lead-free inverted planar photo-voltaic device structure using halide based double perovskite material

Abstract

Owing to the appealing optoelectrical, mechanical, and physical properties, configurable bandgaps, good performance on opaque devices, and low manufacturing cost, Perovskites solar cells are found to be the best alternatives for semi-transparent photo-voltaic (PV) applications. The high absorption coefficient, high carrier mobility, and long carrier diffusion length are inherent features of many organic and inorganic halide perovskite solar cells. Most of the promising perovskite materials contain Lead (Pb) and hence they are toxic. Besides toxicity issues, the stability of these perovskite structures is another key challenge in the process of its commercial production. The performance of various lead-free active PV materials was studied and identified that Cesium–Titanium Halide materials can be a suitable alternate for lead-based perovskite materials. These promising Cs2TiX6 materials have a tunable bandgap between 1.4 eV and 2.3 eV and have balanced electron and hole diffusion lengths. Most of the conventional PSC structure consists of regular planar N-I-P structure and the commercial applications of such devices are bounded due to very high J-V hysteresis and the need for high temperature during fabrication. The primary objective of this work is to optimize and develop an eco-friendly, highly efficient, Cesium-Titanium based novel inverted PV cell structure with all in-organic charge transport materials. The solar cell simulation program, SCAPS – 1D simulator, was used for conducting the numerical study and tested various device structures for obtaining maximum efficiency. The variations in the performance of PV cell structure were analyzed while using assorted absorber materials and inorganic charge transport materials. After the SCAPS-1D based simulation study, a high-performance PSC structure, FTO / MoO3 / Cs2TiBr6 / SnO2 / Au, was obtained. The proposed inverted PV cell structure can produce an excellent power conversion efficiency of 15.68 %, short-circuit current density of 16.59 mA/cm2, an open circuit voltage of 1.1 V, and a fill-factor of 85.76 %.