Growth of ZnBeMgO films by pulsed laser deposition

Band gap tailoring of ZnO with Be and Mg co-doping has proven important for the fabrication of a UV detector. For this purpose the deposition of good quality thin films is very essential. We have deposited Zn $_{1-x-y}$Be$_{x}$Mg$_{y}$O (x=0, 0.10; y=0, 0.10, 0.20) films on sapphire substrate by pulsed laser deposition. The films were deposited using a KrF excimer laser ($\lambda $ = 248nm) with 250 mJ energy and repetition rate of 10Hz at a substrate temperature of 650\r{ }C and O$_{2}$ partial pressure 2mTorr. The films were further annealed at 800\r{ }C for 30 min with 200Torr O$_{2}$ pressure. X-ray diffraction studies revealed the polycrystalline nature of the films. For the band gap calculation, UV measurements were carried out and a blueshift was noticed. The cutoff wavelength for the pristine ZnO film was 370 nm which decreased to 240 nm for 10{\%}Be and 20{\%}Mg co-doped film. This value of Zn$_{0.7}$Be$_{0.1}$Mg$_{0.2}$O film lies in the solar blind region and should be useful for the fabrication of solar blind UV detector. Other studies like morphological, Raman and I-V characteristics of these films are in process and will be presented in the meeting.