Ag diffusion effect on the crystal structure, band structure, and optical property of α-CsPbI3 perovskite materials.

Organic-inorganic perovskite solar cell materials have attracted considerable attention in recent years. Ag and Au are commonly employed as the counter electrode in such cells. In this study, molecular dynamics simulation were used to investigate the diffusion properties of Ag ions in α-CsPbI 3. Ag ions have the highest diffusion coefficient at temperatures between 318 K and 358 K. Density functional theory calculations were performed to study the effects of Ag diffusion on the band structures, crystal structures and optical absorption spectra of α-CsPbI 3 materials. The results suggest that, Ag ions have diffusion coefficients ranging from 0.6 × 10−6 cm2 × s−1 to 1.1 × 10−6 cm2 × s−1 in α-CsPbI 3 at temperatures between 278 K and 398 K. Ag doping can insert a Ag dopant level in α-CsPbI 3 and reduce the band gap of α-CsPbI 3. Furthermore, increasing the Ag content could reduce the energy gap between the Ag dopant level and the valence band or conduction band. • Treat Ag as a dopant to study the Ag diffusion effect in α-CsPbI3. • Using both DFT and MD simulation to discuss the Ag diffusion effect in α-CsPbI3. [ABSTRACT FROM AUTHOR]