An investigation on CdS1-xTex interface compound in CdS/CdTe hetero-junction solar cells by density functional theory (DFT)

• Published in: Superlattices and microstructures Vol. 151; p. 106805
• Main Authors: Halal, Ahmad, Rahman, Kazi Sajedur, Abdullah, Siti Fazlili, Sopian, Kamaruzzaman, Amin, Nowshad
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2021
• Subjects: Band gap; CdS1-xTex alloy; CdTe solar Cells; Density functional theory; GGA+U; CdTe solar Cells; Density functional theory; GGA+U; Band gap; CdS1-xTex alloy
• ISSN: 0749-6036; 1096-3677
• DOI: 10.1016/j.spmi.2021.106805

In this study, we present the structural, optical and electronic properties of zinc blende cadmium sulfide (CdS) and cadmium telluride (CdTe) as well as the intermixed zinc blende ternary CdS1-xTex compound with the compositional variation of S and Te elements. The density functional theory (DFT) method by incorporating the Hubbard model has been utilized to comprehend the relationships between the change of band gap with respect to the molar fraction and its subsequent effects in electronic structures. A 2 × 2 × 2 supercell with 16 atoms has been employed in the molecular design structure of CdTe and CdS. The exchange-correlation potential has been calculated using GGA + U approximation as implemented in the QUANTUM ESPRESSO package along with BURAI software as graphical user interface (GUI). The obtained calculation outcomes are in reasonable agreement with the experimental results in the case of lattice constant and refractive index (n), however, results demonstrate some discrepancy in band gap estimations. The results also exhibit band gap bowing of the ternary CdS1-xTex alloy with the variation of molar fraction (x) which suggest the shrinking of the band gap to the lowest value at x = 0.5 as CdS0·5Te0.5. •Structural, optical and electronic properties are investigated using DFT coupled with the Hubbard model.•The relationships between the change of CdS1-xTex band gap with respect to the molar fraction are extracted.•Calculated lattice constant and refractive index are reasonable with some discrepancy in band gap estimations.•Band gap bowing of CdS1-xTex alloy occurs at the lowest value of x = 0.5 as CdS0·5Te0.5.