ZnS/ZnO heterostructure semiconductor: A promising ionic liquid media approach without calcination

Abstract

ZnS is a wide band gap semiconductor with excellent optical and electrical properties whose electronic structure can be modified with other semiconductors. In this study, ZnS and ZnS/ZnO heterostructure semiconductors were fabricated using the reaction between ZnCl2 and Na2S in the presence and absence of ethyl pyridinium iodide ionic liquid media via a reflux route without calcination. The as-prepared samples were characterized by XRD, FE-SEM, EDS, and DRS techniques. The main observations were the effects of ethyl pyridinium iodide on structural features, morphology, and band gap. The XRD patterns of ZnS represented peaks at 2θ = 8.8, 28.6, 32.9, 47.6, 56.4, 69.7, 76.9º of the blende structure. The crystalline nature of ZnS/ZnO at 29.05, 34.43, 47.51, 56.57, 69.06º and 31.80, 36.26, 47.51, 56.57, 62.85, 66.38, 67.90º is compatible with the standard pattern of ZnS blende and ZnO Zincite phases, respectively. The ZnS/ZnO heterostructure showed that the crystal truncated hexagonal had a thickness of about 90 nm. The rough hexagonal contained several layers, and the averaged elemental enrichment of Zn : S : O was 1 : 0.29 : 0.67. The synergistic effects of ZnS and ZnO promoted band-gap narrowing compared to the ZnS blende particles. So, in the ZnS and ZnS/ZnO cases, the band gap energy was 4.17, and 2.82 eV, respectively. The proposed ZnS/ZnO heterostructure composite has potential applications in semiconductors. The findings of this study opened new aspects of ZnO/ZnS heterostructure in terms of preparation, morphology, and band gap value.

Keywords

• zns/zno heterostructure
• ethyl pyridinium iodide
• narrow band gap
• reflux route