Theoretical exploration of mechanical, electronic structure and optical properties of aluminium based double halide perovskite

• Published in: RSC advances Vol. 12; no. 17; pp. 129 - 1218
• Main Authors: Tang, Tian-Yu, Zhao, Xian-Hao, Hu, De-Yuan, Liang, Qi-Qi, Wei, Xiao-Nan, Tang, Yan-Lin
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 31.03.2022; The Royal Society of Chemistry
• Subjects: Aluminum; Cesium; Chemistry; Density functional theory; Elastic properties; Electronic structure; Free energy; Heat of formation; Optical properties; Optoelectronic devices; Perovskites; Photonic band gaps; Structural analysis
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d2ra01216b

The mechanical, electronic structure and optical properties of aluminium based double halide perovskite were calculated by density functional theory. The formation energy and elastic constant confirm the stability of the cubic perovskite materials. The materials are all ductile and suitable for flexible photovoltaic and optoelectronic devices. The band gap values vary from 0.773 eV to 3.430 eV, exactly corresponding to the range of ideal band gap values for good photoresponse. The band structure analysis shows that all the materials possess small effective mass, which indicates a good transport of carriers. And these materials have a broad energy range of optical absorption for utilization and a detector of photons. Moreover, less expensive K 2 AgAlBr 6 were investigated for comparison with materials containing a cesium element, and according to the results, is also a candidate for photoelectronic devices due to the similar properties. M 2 AgAlX 6 (M = Cs, Rb and K, X = Cl, Br and I) is a stable vacancy ordered double halide perovskite direct band gap semiconductor material with good absorption of near-ultraviolet and short-wavelength visible light.