Synthesis ZnO/ZnTe/Si thin films by Pulsed Laser Deposition for photodetector applications

ZnTe/ZnO nano-heterostructure ZnTe and ZnO nanofilms were grown by pulse laser deposition technique for photodetector applications . The films were deposited on n-type silicon and FTO glass substrate at (180 mj, 700 and 900 pulses) . The structural properties were studied by X-ray diffraction patterns , it showed that the film have crystallized hexagonal and cubic structures . The elemental compositions of the thin ZnTe and ZnO films were identified through energy dispersive X-ray (EDX) analysis . FE-SEM examinations show that the films show good homogeneity of particles distributed on the surface and that the average particle size increases with the increase in the number of laser pulses . Silver (Ag) electrodes were deposited on ZnTe/ZnO/Si films and detector characteristics were performed, including (I-V) in illuminated and dark conditions. The photosensitivity studies show that the maximum detector's responsivity was 31.892 µA/mW at 460 nm. The highest values of specific detectivity and External quantum efficiency were 3.26 ×1017Jones and 96.075% , respectively. The ON/OFF measurement was performed to investigate the response/recovery time and switch behavior of the photodetectors .