P-type ZnO nanorods were successfully synthesized with antimony (Sb) doping by hydrothermal method. The morphology of Sb-doped and undoped ZnO were observed by Scanning electron microscope, X-ray diffraction, and Transmission electron microscope. According to photoluminescence spectra, Sb doped into ZnO can create more defects inside the material, which can enhance green illuminations. Consequently, the bandgap of doped samples was slightly narrowed because of more defect levels and indicated by the red shift of the near band edge emission in UV-Vis spectra.
Especially, Sb-doped ZnO was demonstrated as p-type semiconductor through X-ray photoelectron spectroscopy and Seebeck coefficient. The photodetections of Sb-doped ZnO are reproducible and more sensitive under green illumination compared to undoped ZnO nanorods. This enhancement of responsivity is attributed to O vacancies (VO) and Zn interstitials (Zni). By further comparing different estimated doping concentrations, the responsivity and light current increase as doping concentration increases. Besides, Seebeck coefficient of undoped and doped samples shows negative and positive value, it demonstrates that Sb doped into ZnO turns ZnO nanorods from n-type to p-type. Seebeck coefficient of p-type ZnO gradually increases as increasing temperature, attributed to the hole thermal excitation. By controlling the doping concentration, ZnO materials can switch from n-type to p-type at typical temperature.

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