Shakeel Ahmad KhandySaamin Gowhar VaidIshtihadah IslamAurangzeb Khurram HafizJENG-DA CHAI2021-07-282021-07-2820219258388https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101359228&doi=10.1016%2fj.jallcom.2021.158966&partnerID=40&md5=e5172400d489bfcabb835a5707488e7ehttps://scholars.lib.ntu.edu.tw/handle/123456789/573478Here we discuss the electronic structure and optical properties of Yb based halide perovskites with keen interest on phonon and mechanical stability using the HSE06 approximated density functional theory calculations. The experimental structural parameters are exploited to calculate the semiconducting band structures with energy gap of 4.32 eV and 3.68 eV for CsYbCl3 and CsYbXBr3 alloys, respectively. Cubic phase stability is guaranteed by the phonon dynamics and machinability of these structures. The observed relaxed structural parameters are in accord with the previous experiments. We found that the present halide perovskite compounds are semiconductors with tuneable band gaps and the f-states of Yb element play a significant role in defining the electronic structure. In addition to this, the sound velocities accompanied by the Debye temperatures (181 K for Cl and 141 K for Br) are evaluated. Furthermore, the dielectric constant optical conductivity, electron loss function, refractive index provide a fundamental basis of the feasible optical characteristics suitable for optoelectronic devices and applications. ? 2021Cesium alloys; Chlorine compounds; Density functional theory; Electronic structure; Energy gap; Mechanical stability; Optical conductivity; Optoelectronic devices; Perovskite; Phonons; Refractive index; Vanadium alloys; Ytterbium compounds; Electron loss; Electronic structure and optical properties; Halide perovskites; Optical characteristics; Optoelectronic applications; Phonon dynamics; Semiconducting band structure; Structural parameter; Ytterbium alloys[SDGs]SDG7journal article10.1016/j.jallcom.2021.1589662-s2.0-85101359228