Research

Synthesis of optically active hierarchical zNs/znO hetoerostructures

ZnO is a wide band gap semiconductor of 3.37 eV and high exciton binding energy of 60 meV at room temperature, and ZnO films are highly transparent which creates chances for ZnO to become an essential element in optoelectronic devices. There is an interchangeable conversion between ZnO and ZnS. Recently, new approaches to obtain one-dimensional nanostructures of ZnO with various morphologies based on ZnS as a precursor have been studied and vice versa. Various ZnS/ZnO heterostructures and hierarachical ZnS/ZnO heterostructures such as ZnO/ZnS heterojunction nanoribbons, ZnO/ZnS nanobelt and nanowire heterostructures, and ZnO/ZnS coaxial cables were fabricated. This has motivated us to study optically active hierarchical ZnS/ZnO heterostructures for optoelectronics and photonics application.

A facile fabrication method of surface oxygen vacancies and tHeir contribution to the photoluminescence

With its large band gap of 3.37 eV that emits UV radiation when excited, intrinsic ZnO is not considered as an ideal luminescent material. However, by introducing defects, the photoluminescence of ZnO can be intervened, enabling the emission of visible light of different colors, including violet, blue, green, yellow, and red. These emissions are associated with various types of defects in ZnO, including O vacancy (VO), Zn vacancy (VZn), O interstices (Oi) and Zn interstices (Zni). However, the origins of different defect emissions are still highly controversial. This has motivated us to study Surface oxygen vacancies of ZnO.