TMDC Material Integration as Buffer Layer for Cost-Effective and High Performance CIGS Solar Cell

In this study, the significance of reducing indium usage in CIGS solar cells is emphasized due to the scarcity and expense of this material. Employing proper tuning of the CIGS layer bandgap and electron affinity, the research aims to minimize the reliance on indium. SCAPS-1D software is utilized in the research to evaluate the performance of a single-junction solar cell featuring CIGS as the absorber material. This evaluation incorporates the use of TMDC materials such as WS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and WSSe as buffer layers, aiming to avoid the toxicity typically associated with CdS. It is found that CIGS cells with a WSSe buffer layer exhibit an enhanced efficiency of 25.99% with a reduced indium content of $\mathbf{3 6 \%}$. Moreover, integrating a CGS back surface field layer enhances efficiency ($\sim \mathbf{2 7. 7 1 \%}$) while reducing CIGS thickness, thus decreasing indium usage and improving cost-effectiveness. Subsequently, the optimization of cell thickness and doping density contributes to overall performance enhancement. Notably, a maximum power conversion efficiency (PCE) of $\mathbf{2 7. 8 6 \%}$, Voc of 1.044 V, Jsc of $31.73 \mathrm{~mA} / \mathrm{cm}^{2}$, and FF of 84.06% is achieved for the optimized Al/Al: $\mathrm{ZnO} / \mathrm{WSSe}{(150 \mathrm{n m})}$/ CuIn ${ }_{0.36} \mathrm{Ga}_{0.64 \mathrm{Se}_{2}}$ (1000nm)/CGS $(1000 \mathrm{~nm}) / \mathrm{Mo}$ based solar cell device with a temperature coefficient of $\mathbf{- 0. 1 4 1 \%}$ per °C. This research offers a viable approach to enhance the efficiency of CIGS solar devices while simultaneously reducing reliance on expensive indium materials.