Structural, electronic and optoelectronic properties of AB ₅ C ₈ ( A = Cu/Ag; B = In and C = S, Se and Te ) compounds

Abstract

Summary Ternary semiconductors AB5C8 (A = Cu/Ag, B = In and C = S, Se or Te) have been investigated. The CuIn5S8 and AgIn5S8 have been synthesize in cubic spinel structure with space group (Fd3m), whereas CuIn5Se8, AgIn5Se8, CuIn5Te8 and AgIn5Te8 have tetragonal structures with space group P‐42m. The relaxed crystal geometry, electrical properties such as electronic band structure and optoelectronic properties are predicted by using full potential method in this work. For the determination of relaxed crystal geometry, the gradient approximation (PBE‐GGA) is used. All the studied compounds are semiconductors based on their band structures in agreement with the experimental results, and their bulk moduli are in the range 35 to 69 GPa. Wide absorption peaks appeared in the visible to ultraviolet energy region indicating good absorption ability of these compounds. Therefore, these semiconductors are an excellent choice for optical devices, electrochemical and photovoltaic cells. These compounds have remarkable characteristics such as direct as well as indirect band gaps with very slight difference between the two, high absorption coefficient, good photo‐stability, easy inter‐conversion between n‐ and p‐type semiconductors and in manufacturing of comparatively cheap homo and hetero junction structures. AB5C8 (A = Cu/Ag; B = In and C = S, Se, Te) compounds have shown high absorption and optical conductivity in the visible region. These compounds have therefore high potential to be used as solar energy harvesting. Also these systems are optical active in the ultraviolet region too therefore can be used for high frequency optoelectronics applications.

Heterojunction Engineering of Multinary Metal Sulfide‐Based Photocatalysts for Efficient Photocatalytic Hydrogen Evolution

“…[127,128] The optical properties of AgIn 5 S 8 , such as photoconductivity, optical absorption, Raman scattering, IR reflection, and photoluminescence (PL) have been extensively explored in the literature. [129,130,131,132,133] In view of the excellent semiconductor properties, Qasrawi et al have studied the influence of heat treatment, temperature, and light intensity on the photoelectric properties and structure stability of AgIn 5 S 8 thin film. [134,135,136] The authors have proved that the thermally fabricated AgIn 5 S 8 thin film possesses excellent photoelectric properties, which might have a great potential in PHE application.…”

Recent advances in photocatalytic hydrogen evolution of AgIn5S8‐based photocatalysts

“…[50] Among them, the AgIn 5 S 8 possesses the suitable bandgap of 1.7-2.0 eV and high light absorption coefficient, which can effectively realize the visible-light PHE. [51][52][53][54][55][56][57] Compared with the mature and intensively studied BMS of CdS, AgIn 5 S 8 not only displays high photostability but also composes of nontoxic elements. Therefore, it has a better potential to achieve the efficient PHE.…”