Effects of ambient oxygen pressures and substrate temperatures in pulsed laser deposited Zn0.85Li0.15O thin films

Li doped zinc oxide Zn1−xLixO (x = 0.15) thin films were grown by using the pulsed laser deposition method. The depositions were done onto Pt(111)/Ti/SiO2/Si(100) substrate set at temperatures ranging from 300 °C to 700 °C, with varying the ambient O2 pressure range of 3-20 mTorr. The effects of substrate temperatures and ambient O2 pressures on the surface morphology and structural properties of the Zn0.85Li0.15O thin films were investigated by using the scanning probe microscopy and X-ray diffraction spectra, respectively. Also the chemical structures of the films were investigated by observing the X-ray photoelectron spectra of the core and shallower levels. We observed the deep blue PL emissions centered at about 390 nm (3.20 eV) from the Zn0.85Li0.15O thin films. It was investigated with respect to the ambient O2 pressures during the deposition. It is considered that the deep blue PL emission in the Zn0.85Li0.15O thin film may be related to the incorporation of oxygen vacancies.