Moss-Burstein shift in La-doped BaSnO_3; A novel electron transport layer material for hybrid halide perovskite solar cells

摘要

Highly efficient hybrid (organic-inorganic) halide perovskite solar cells (PSCs) employ TiO_2 as electron transport layer (ETL) but it impedes the device stability under solar illumination. Therefore, there is an imperative need to study the materials that can be the ideal replacement for TiO_2 as ETL. With its growth at mild conditions recently by Shin et al. [Science, 356, 167 (2017)], La-doped BaSnO_3 (LBSO) emerges out as an efficient candidate for ETL in PSCs. In this direction, we represent first-principles electronic properties and optical response of pristine and La-doped BaSnO_3 using full potential linear augmented plane wave (FPLAPW) method within time efficient orbital independent modified Becke Johnson (mBJ) approach. Post La-doping, Moss-Burtsein shift is observed in BaSnO_3 that establishes it as an excellent n-type transparent conducting oxide. The optical absorption spectra of LBSO has been analyzed to prove almost full transmittivity for energy ≤ 4eV which affirms LBSO as an ideal material for ETL in various PSCs.