Performance improvement of perovskite/CIGS tandem solar cell using barium stannate charge transport layer and achieving PCE of 39 % numerically

Abstract

The way to overperform the Shockley-Quisser limit of power conversion efficiency (PCE) for single junction solar cell is tandem device. In this work, a perovskite solar cell (PSC) and Copper Indium Gallium Selenide (CIGS) based solar cell (CSC) are individually optimized and implemented as PSC/CSC tandem (PSSC) device in SCAPS-1D. The perovskites which are highly stable and optically fit for PSSC, consists of triple or quadruple mixed cations, lead (Pb) and halides and the most popular perovskite of this kind is Cs0.15MA0.15 FA0.70Pb(I0.85Br0.15)3 which is used as absorber material in the PSC presented in this work. Another important aspect of PSC is selection of suitable material for charge transport layers. For the first time, a never explored before the oxide perovskite namely the barium stannate (BaSnO3) is used as electron transport layer (ETL) along with NiO as hole transport layer (HTL) in the reported PSC which provides impressive short circuit current density (JSC), open circuit voltage (VOC), fill-factor (FF) and PCE of 23.89 mAcm−2, 1.48 V, 88.92 %, 31.53 % respectively. Moreover, a comprehensive analysis of the PSC without HTL but with BaSnO3 as ETL is carried out and improved records are observed. Finally, the optimized PSSC which consists of HTL free PSC and CSC can deliver a PCE as high as 39 % which is the highest ever predicted value and is attributed to the well-matched energy band alignment of BaSnO3 with the absorber. This work can be a potential contributor to the high efficiency solar cell fabrication roadmap.