First-principles study of electronic and optical properties of lead-free double perovskites Cs2NaBX6 (B = Sb, Bi; X = Cl, Br, I). (June 2018)

• Record Type: Journal Article
• Authors: Zhao, Shuai; Yamamoto, Kumiko; Iikubo, Satoshi; Hayase, Shuzi; Ma, Tingli
• Is Part Of: Journal of physics and chemistry of solids. Volume 117(2018)
• Page Start: 117
• Page End: 121
• Publication Date: 2018-06
• Subjects: Lead-free perovskites -- Electronic structure -- Density functional theory; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2018.02.032
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Organolead halide perovskite is regarded as the most promising light-harvesting material for next-generation solar cells; however, the intrinsic instability and toxicity of lead are still of great concern. Bismuth is ecofriendly and has electronic properties similar to those of lead, which has gradually attracted interest for optoelectronic applications. However, the valence state of bismuth is different from that of lead, eliminating the possibility of replacing lead by bismuth in organolead halide perovskites. To address this matter, one feasible strategy is to construct B -site double perovskites by the combination of Bi 3+ and B + in 1:1 ratio. In this work, lead-free halide double perovskites of the form Cs2 Na BX 6 ( B = Sb, Bi; X = Cl, Br, I) were investigated by first-principles calculations. The electronic properties, optical absorption coefficients, and thermodynamic stability of these compounds were investigated to ascertain their potential application in solar energy conversion. The results provide theoretical support for the exploration of lead-free perovskite materials in potential optoelectronic applications. Graphical abstract: Highlights: A series of lead-free double perovskites were studied by density functional theory. The electronic properties of these perovskites were calculated with spin-coupling effects. The formation enthalpy was computed to assess the thermodynamic stability of these perovskites.