Role of swift heavy ions irradiation on the emission of boron doped ZnO thin films for near white light application

Boron doped ZnO (ZnO:B) thin films on silicon substrates were synthesized with the sol-gel method using the spin coating technique. The films were irradiated by 80 MeV Br⁺⁶ ions at various ion fluences. The X-ray diffraction results indicate that ZnO:B crystallized in the normal hexagonal wurtzite structure of ZnO. X-ray photoelectron spectroscopy data indicated that the O1s peak consist of three components designated as O1 (coming from ZnO), O2 (coming from defects) and O3 (coming from adsorbed species). Defect level emission (DLE) was obtained in the luminescence spectra of the pristine ZnO:B sample while the strong UV emission was observed for the ion irradiated films. The intensity of the DLE emission decreased after irradiation while the band to band emission increased after ion irradiation. A direct correlation between the amount of defects (O2 peak of XPS) and the DLE was observed. The emission of the ZnO:B is exponentially correlated with the swift heavy ion induced stress and the amount of defects. These ZnO:B thin films may be used for near white light emission applications.