Nanostructured ZnO network films deposited on Al2O3 substrates by chemical bath deposition

The evolution behavior of structures and photoluminescence of K-doped ZnO thin films under different annealing temperatures

“…Some groups found that undoped ZnO thin films have blue emission [27,28], while others found that doped ZnO thin films have blue emission [29,30]. This indicates that the blue emission is connected with both native point defects such as Zn interstitial and Zn vacancy and doped impurities.…”

Microstructure and blueshift in optical band gap of nanocrystalline AlxZn1−xO thin films

“…For the blue emission of ZnO material, although some related results have been reported, but the emission mechanism of blue light is still unclear. Some research groups found that undoped ZnO thin films have blue emission[37][38], while others found that doped ZnO thin films have blue emission[39- 40]. This indicates that the blue emission is concerned with both native point defects such as Zn interstitials and Zn vacancies, and doped impurities.…”

Nanostructured zinc oxide thin film by simple vapor transport deposition

“…The UV emission peak at 378 nm corresponds [20] to near band edge emission which comes from the recombination of free excitons [21] through an exciton-exciton collision process. It is reported that both undoped and doped ZnO films exhibit blue emission [22,23] The blue emissions at 436 nm and 464 nm in ZnO films are related to both native point defects such as Zn interstitial and Zn vacancy. The defect related emissions are sensitive to the preparation process, thereby the nano structures.…”