UV-photodetector based on heterostructured ZnO/(Ga,Ag)-co-doped ZnO nanorods by cost-effective two-step process
In the present work, we have fabricated, characterized and tested the hetero-structured zinc oxide/[gallium, silver]-co-doped zinc oxide (ZnO/[Ga,Ag]-co-doped ZnO) ultraviolet (UV)-photodetector (PD) using a cost-effective two-step process. In this, the results of our study are reported and discussed for the first time. X-ray diffraction (XRD) analysis ensures that the prepared samples are well-crystallized and show a hexagonal-wurtzite ZnO structure. The scanning electron microscopy (SEM) confirmed nanorods growth in a hexagonal shape on the film surface, which is the key point in the enhancement of the photoresponse. The fabricated UV-photodetector ZnO/[Ga,Ag]-co-doped ZnO achieved a phtotoresponse of 40% with a rapid switching rate that was three times greater than that of the pristine ZnO at UV light intensity of 13.5 mW/cm2 and proportional to the illumination intensity. The highest responsivity of Rp = 1424.5 A/W and photoconductive gain of G = 4800 were achieved at a UV light exposure of 13.5 mW/cm2 with applied voltage (bias) of 5 V. This could be ascribed to the clear substitution of Ga and Ag in the ZnO, which enhanced the UV sensing properties.