MgxZn1−xO films synthesized by laser sintering method and UV detectors

Abstract As a type of energy, laser has extensively applied for fabricating metals, but barely for preparing inorganic oxide materials. Herien, the novel laser sintering technology was used to synthesize MgxZn1−xO films on quartz substrates. XRD patterns show that all films grow along c-axis orientation and have a wurtzite structure. The films display hexagonal surface morphology and the average grain size of films increases with the Mg doping content up to 30% and then decreases when Mg concentration is more than 30%. In the visible light region, the transmittance of this film is high and no multi-absorption edges are surveyed, suggesting the absence of phase segregation in the grown films. The band-gap increases from 3.36 eV to 4.75 eV, corresponding the Mg component increase from x = 0.1 to x = 0.45. The devices exhibit a broad response peak ranging from 340 nm to 290 nm, covering a large portion of from UVA to UVC light. The Mg0.3Zn0.7O detector exhibits the low dark current (0.23 nA), high photocurrent (96.1 μA) and high photo/dark current ratio of 4.18 × 105. Correspondingly, the detectivity of 5.46 × 1013 Jones and responsivity of 0.665 A/W are also achieved. This technology not only improves the Mg concentration in MgxZn1−xO thin films but also provides a novel fabrication process for growth of UV photodetector films.