One-Step Gas-Solid-Phase Diffusion-Induced Elemental Reaction for Bandgap-Tunable Cu_aAg_m1Bi_m2I_n/CuI Thin Film Solar Cells.

ABSTRACT: Lead-free inorganic copper-silver-bismuth-halide materials have attracted more and more attention due to their environmental friendliness, high element abundance, and low cost. Here, we developed a strategy of one-step gas-solid-phase diffusion-induced reaction to fabricate a series of bandgap-tunable Cu_aAg_m1Bi_m2I_n/CuI bilayer films due to the atomic diffusion effect for the first time. By designing and regulating the sputtered Cu/Ag/Bi metal film thickness, the bandgap of Cu_aAg_m1Bi_m2I_n could be reduced from 2.06 to 1.78 eV. Solar cells with the structure of FTO/TiO₂/Cu_aAg_m1Bi_m2I_n/CuI/carbon were constructed, yielding a champion power conversion efficiency of 2.76%, which is the highest reported for this class of materials owing to the bandgap reduction and the peculiar bilayer structure. The current work provides a practical path for developing the next generation of efficient, stable, and environmentally friendly photovoltaic materials.

SUBMITTER: Fan E 

PROVIDER: S-EPMC9981855 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature