Electrical properties of tandem solar cells based on films of organic-inorganic perovskites deposited on thin-film silicon solar cells

This study presents an analysis of the morphological and electrical properties of multilayer structures fabricated using thin films of organometallic halide perovskites (OHP), specifically CH$_3$NH$_3$PbI$_3$, deposited onto the surface of crystalline silicon ($c$-Si)-based solar cells. The structural morphology and electrical characteristics of these multilayered configurations were investigated through atomic force microscopy (AFM), current-voltage (I–V) characterization, and impedance spectroscopy. The AFM observations revealed significant morphological variations among the produced samples. I–V analysis conducted at 300 K indicated that all samples exhibited enhanced photoconductivity relative to pure $c$-Si, suggesting a beneficial influence of the perovskite layer. Impedance spectroscopy analysis revealed that in the absence of light, a sample with a perovskite layer on $c$-Si displayed two semicircles in its Nyquist plot, implying the coexistence of two distinct processes, such as ion diffusion or charge recombination. These processes appear to converge into a single mechanism upon exposure to light, a change attributed to the altered concentration of charge carriers. The findings of this research pave the way for further optimization and enhancement of the performance parameters of advanced tandem $c$-Si solar cells with top layers composed of organometallic halide perovskites.