An Exploration of Photovoltaic Performance of the Rb2SnI6 using DFT and SCAPS-1D

Perovskite with organic and lead-based cations work well, but their toxicity and stability have hindered their commercialization. In this study, we used WIEN2k software to perform first-principles calculations based on density functional theory (DFT) framework to determine the optical and electronic properties of the proposed perovskite material Rb
2
SnI
6
to be used as an absorber for solar cells (SCs). The DFT results for band gap, carrier mobility, effective densities, and absorption spectra are put into the SCAPS (Solar Cell Capacitance Simulator)-lD software to estimate how well the proposed perovskite solar cell (PSC) structure (FTO/TiO
2
/Rb
2
SnI$\epsilon$/PTAA/Au) will work as a photovoltaic device. TiO
2
and PTAA are employed as electron and hole transport materials respectively. We have also investigated the device performance with different organic hole transport layers (HTLs). The optimized series resistance ($\mathrm{R}_{\mathrm{s}}$) of 1 $\Omega$. cm
²
, Shunt resistance ($\mathrm{R}_{\mathrm{s}\mathrm{h}}$) of 1$ 0^{4}\Omega$. cm
²
, defect density of 10
¹³
c$\mathrm{m}^{-3}$, and thickness of 0.8 $\mu$m was used for the final simulation. The proposed device after optimization exhibits a $\mathrm{J}_{\mathrm{s}\mathrm{c}}$ of 40.4 mA/c$\mathrm{m}^{2},\mathrm{V}_{\mathrm{o}\mathrm{c}}$ of 0. 72V, FF of 79.7 %, and PCE of 22.4 %. We also investigated the quantum efficiency (QE) of the proposed PSCs. Combination of this computational and simulation analysis of non-toxic Rb
2
SnI6 double perovskite (DP) reveals that it is advantageous for potential SC applications.