Effect of Bi doping on the opto-electronic properties of ZnO nanoparticles for photodetector applications

Bi (0, 1, 3 and 5 wt%) doped ZnO nanopowders were generated in this study using a simple and inexpensive wet chemical method. X-ray diffraction, Fourier-transform infrared spectroscopy, Scanning electron microscopy, photoluminescence spectroscopy, UV-Vis-DRS, studies are used to evaluate the effect of dopants in ZnO sample. Crystallite size and grain size of the samples were reduced and enhanced the surface to volume ratio due to Bi doping. Oxygen vacancies and shrinkage of bandgap plays a significant role in enhancement of photosensing property. Bi doped ZnO nanopowders had better photosensing activity than pristine ZnO nanopowders. Also, the doped metal ions improved the photosensing efficiency by increasing electromagnetic wave absorption and inhibiting the recombination rates of charge carriers resulting raise of hole-electron pair production. The significant photosensing parameters responsivity (R), detectivity (D*) and external quantum efficiency (EQE) of the 3 % of Bi doped ZnO sample exhibited maximum values such as 0.163 AW-1, 1.26 x 1010 Jones and 53% respectively. The findings of this present study show that the3 % Bi doped ZnO can be an excellent photosensing material.