Enhanced Efficiency of Semitransparent Perovskite Solar Cells via Double-Sided Sandwich Evaporation Technique for Four Terminal Perovskite-Silicon Tandem Application.

Halide perovskite based solar cells (PSC's) have shown tremendous potential based on its facile fabrication technique, and the low cost of perovskite thin film formation with efficiency passing through an unmatched growth in recent years. High quality film along with morphology and crystallinity of the perovskite layer influences the efficiency and other properties of the perovskite solar cell (PSC). Furthermore, semitransparent perovskite solar cells (ST-PSC) are an area of attraction due to its application in tandem solar cells, although various factors like suitable transparent rear electrodes and optimized technique limit the power conversion efficiency (PCE). In this article, we fabricated perovskite film using a technique termed Double-sided sandwich evaporation technique (DS-SET) resulting in high quality perovskite film (MAPbI and MAPbICl). Using this fabrication approach as compared to the traditional spin-coating method, we reported an enhanced photovoltaic performance of the PSC with a better surface morphology and homogeneity. The best parameter via DS-SET was found to be SET 30 min, which demonstrated a PCE (%) up to 14.8% for MAPbI and 16.25% for MAPbICl, respectively. Addressing the tandem solar cell, incorporating thin Ag as a transparent electrode with a thickness of 20 nm onto the PSC's as the top cell and further combining with the Si solar cell results in the four terminal (4T) tandem solar cell exhibiting a PCE (%) of 24.43%.