Formamidinium dopant effects on double perovskite Cs2AgBiBr6. Issue 4 (17th November 2021)

• Record Type: Journal Article
• Authors: Zhang, Cai‐Rong; Chen, Hong; Liu, Zi‐Jiang; Zhang, Mei‐Ling; Wang, Wei; Wu, You‐Zhi; Chen, Hong‐Shan
• Is Part Of: International journal of quantum chemistry. Volume 122:Issue 4(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-17
• Subjects: charge carrier mobility -- doping -- double perovskite Cs2AgBiBr6 -- electronic structures -- formamidinium; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.26846
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: The optoelectronic properties of formamidinium CH(NH2 )2 + (FA) doped double perovskite Cs2 AgBiBr6 with corresponding formula Cs1.875 FA0.125 AgBiBr6 were investigated based on electronic structures and supercell models. The dopant formation energies, tolerance and octahedral factors support the doped structures are stable. FA dopant increases band gap about 0.15 eV without introducing dopant states in gap, but also increases the reduced effective masses, exciton binding energies, and elastic constants. However, it decreases exciton energies and charge carrier mobilities. Though the energy barriers among the different FA orientations in Cs1.875 FA0.125 AgBiBr6 are quite small (<30 meV), FA orientations in doped systems can remarkably impact on electron and hole mobilities. Abstract : Using first‐principles density functional theory, the substitution of FA for Cs atoms to obtain double perovskite Cs1.9375 FA0.0625 AgBiBr6 was studied. The influence of five different FA orientations on the optical and electrical properties of Cs1.9375 FA0.0625 AgBiBr6 was discussed. Those results will help to develop new double perovskite materials by adjusting the optoelectronic properties of doping.