Effects of SiC buffer on the structural and photoelectrical properties of ZnO thin films grown on Si(1 1 1) by PLD

The films of ZnO/SiC/Si(1 1 1) and ZnO/Si(1 1 1) were grown by the pulsed-laser-deposition (PLD) technique and were processed to fabricate ultraviolet (UV) detectors. The effects of SiC buffer on the structural and photoelectrical properties of ZnO thin films grown on Si(1 1 1) substrates were investigated by the X-ray diffraction (XRD), photoluminescence (PL), current–voltage (I–V) and photoresponse measurements. The results show that the SiC buffer not only leads to better crystalline quality and higher intensity of luminescence at 380 nm of ZnO thin film, but induces lower leakage current and much better photoresponse of UV detector. A compliant SiC buffer layer can relax partial stress induced by large lattice and thermal mismatch between ZnO and Si and reduce the interface defects and interface state density, which can effectively improve the crystalline quality as well as optical and photoelectrical properties of the ZnO thin film grown on Si substrate.