The anisotropic optical properties of different polytypes (ε,β,δ,γ) of GaSe lamellar materials

Abstract

In this paper, we have calculated the optical properties of the different polytypes of GaSe lamellar materials. The calculations are based on the DFT method and is performed using the CASTEP code. All optical properties have been studied in a domain that extends energetically from 10 meV to 35eV and have been measured for a polarization // and ⊥ with the c axis. A strong anisotropic was observed, which indicates that the optical properties of the GaSe material are essentially determined by the symmetry of a single layer, exactly by the symmetry resulting from the stacking of the layers. The study of the optical properties of the semiconductor GaSe, shows anisotropic optical behavior. In addition, the absorption starts in the UV-Visible spectral range, the peaks appear in the UV range, which is important for photovoltaic applications. Our results are important and give a great chance to these lamellar materials for wide use and various applications.

Ab Initio Investigation for Solar Technology on the Optical and Electronic Properties of Double Perovskites Cs2AgBiX6(X=Cl, Br, I)

“…In this study, we focus on the study of Cs 2 AgBiX 6 , the total energies of this perovskite were calculated with the ab-initio simulation package CASTEP. [36][37][38][39] The GGA approach treats exchange and correlation functions by employing the Perdew, Burke, and Ernzerhof (PBE) approximation. [39][40][41][42][43] A Monkhorst-Pack grill mounted on a 4x4x4 for integration into the Brillouin zone.…”

“…[36][37][38][39] The GGA approach treats exchange and correlation functions by employing the Perdew, Burke, and Ernzerhof (PBE) approximation. [39][40][41][42][43] A Monkhorst-Pack grill mounted on a 4x4x4 for integration into the Brillouin zone. The electrons taken into consideration for the atoms Cs Ag Bi Cl Br , , , , , and I are 5s 2 5p 6 6s 1 , 4d 10 5s 1 , 6s 2 6p 3 , 3s 2 3p 5 , 4s 2 3d 10 4p 5 , and 3s 2 3d 10 5p 4 , respectively.…”

Polytypism and Packing-Dependent Colossal Positive and Negative Thermal Expansion in a 2D Layered Cerium-Based Coordination Polymer

“…Polytypism is an abundant phenomenon in chemistry and crystallography, which plays an important role in numerous solid-state systems. − In the structure of a compound prone to polytypism, atomic layers or layered structural units may adopt different stacking motifs, thereby yielding two or more crystalline modifications known as polytypes. − For certain systems (e.g., SiC and CdI 2 ), crystallographic data include up to hundreds of polytypes. , The latter differ not only in their crystal structure but also in structure-related physical characteristics (optical properties, − thermal conductivity, , band structure, − crystal “hopping” effect, and even superconductivity) that makes them a versatile platform for the development of functional materials with tunable properties.…”

Anisotropic van der Waals Tellurene-Based Multifunctional, Polarization-Sensitive, In-Line Optical Device

“…7,8 These endeavors have yielded a diverse array of inline optical fiber devices based on 2D materials, encompassing applications in ultrafast lasers, 5,8 parameter converters, 6 optical modulators, 9,10 and photodetectors. 11 Notably, specific 2D materials, like black phosphorus (BP), 12 β-GaSe, 13 α-In 2 Se 3, 14 and ReS 2, 15 exhibit a low in-plane lattice symmetry and manifest optical polarization-sensitive responses. Devices utilizing these anisotropic 2D materials introduce polarization as an additional dimension for modulation and multiplexing within optical networks, thereby complementing the conven-tional dimensions of intensity and wavelength.…”