Evaluating the Potential of Lead‐Free Nontoxic Cs₂BiAgI₆‐Based Double Perovskite Solar Cell

Abstract

Recently, the efficiency of single‐junction perovskite solar cells has been competing with the crystalline Si solar cells. However, the perovskite absorbers are toxic and susceptible to moisture. Herein, the performance of an environmentally benign and durable Cs2BiAgI6 light harvester using the 1D Solar Cell Capacitance Simulator (SCAPS‐1D) software package is evaluated. The primary physical parameters, namely, defect and doping densities and thickness of the subsequent layers, are varied to achieve high efficiencies. The optimized Cs2BiAgI6‐based double perovskite solar cells with three distinct hole‐transporting layers (HTLs) (i.e., MoO3, CuSCN, and spiro‐OMeTAD) deliver a power conversion efficiency of ≈29% with AZnO as electron transport layer (ETL). Further, a variety of possible rear electrodes are explored, and their effect on the performance is estimated. For real‐time examination of the Cs2BiAgI6‐based double perovskite solar cells, the variation of power conversion efficiency (PCE) concerning the operating temperature is estimated. The thickness of the Cs2BiAgI6 light harvester layer and the bulk defect density are the key aspects in attaining high power conversion efficiencies in Cs2BiAgI6‐based double perovskite solar cells.

An In‐Depth Investigation of the Combined Optoelectronic and Photovoltaic Properties of Lead‐Free Cs2AgBiBr6 Double Perovskite Solar Cells Using DFT and SCAPS‐1D Frameworks

“…[ 33,35,41,42 ] Due to the continuous improvement of the PSCs, there are some ETLs and HTLs that are not frequently used. Among them aluminum doped zinc oxide (AZnO), [ 43 ] cadmium zinc oxide (CdZnS), [ 44 ] La‐doped BaSnO 3 (LBSO), [ 45 ] niobium pentoxide (Nb 2 O 5 ) [ 46 ] make good band alignments with Cs 2 AgBiBr 6 absorber. In the case of HTLs, copper zinc tin selenide (CZTSe), [ 44 ] cadmium telluride (CdTe), [ 47 ] copper nickel tin sulfide (CNTS), [ 44 ] nitrogen‐doped titanium dioxide (TiO 2 :N), [ 48 ] poly(triarylamine) (PTAA), [ 49 ] nickel cobaltite (NiCo 2 O 4 ), [ 50 ] antimony sulfide (Sb 2 S 3 ), [ 51 ] n‐propyl bromide (nPB), [ 52 ] gallium arsenide (GaAs), [ 53 ] Zinc telluride (ZnTe) [ 54 ] makes good band alignment with Cs 2 AgBiBr 6 , although they are not used frequently.…”

Non‐Toxic and Stable Double Perovskite Solar Cells Based on Cs2AgSbX6 Light Harvester: First Principle Calculations‐Aided Theoretical Estimation

“…[ 1 ] The carcinogenic lead (Pb) ions found in the perovskite light harvesters facilitate, panchromatic visible light absorption emanating from the filled 6 s and empty 6 p orbital at conduction band maximum and valence band minimum, respectively. [ 2,3 ] Thus, to mitigate toxicity, the Pb cation was replaced by divalent Sn or Ge cations. Nevertheless, the Sn 2+ and Ge 2+ cations comprise higher energy 4 s and 5 s orbitals, respectively, rendering oxidation centers, which limit their long‐term stability.…”