UV-visible detector and LED based n-ZnO/p-Si heterojunction formed by electrodeposition

In this study, we have investigated the heterojunctions formed by n-ZnO thin films deposited on (100) p-Si:B using electrochemical deposition (ECD) technique. Structural, electrical and luminescence features of the thin films were respectively measured. Optimal sets of growth conditions seem to be the ones that are undergone for the samples D1 and D2. It was observed that n-ZnO thin films have dominantly preferred orientation of (002). It has been shown that the heterostructures exhibited reasonable rectifying behavior with turn-on voltage of about 1.2 V and ideality factor of 2.1. In case of illumination with 400 nm wavelength light, significant increase occurred especially in reverse bias current by a factor of 103 and 102 for the D1 and the D2, respectively. Bandgap of ZnO thin films has been determined to be 3.4 eV at the room temperature by using the band edge photoluminescence measurements. Finally, the room temperature electroluminescence (EL) results show that the heterostructures exhibits observable broad luminescence centered at the wavelengths of 390 and 510 nm for D1 and 470 nm for D2, respectively. Additionally, sharp lasing peaks are also observed in the EL spectra, probably due to the multiple scattering effects.