Microwave-assisted fabrication and characterization of p-ZnO:(Ag,N) nanorods/n-Si photodetector

• p-ZnO:(Ag,N) nanorods/n-Si photodetector was fabricated by microwave-assisted chemical bath deposition (CBD) method.
• The energy band diagrams of heterojunctions were constructed to clarify the I–V characteristics.
• The UV photodetector shows a sharp cutoff of responsivity and a high UV-to-visible rejection ratio.

ZnO:(Ag,N) nanorods (NRs) were vertically grown on n-type Si substrate by microwave-assisted chemical bath deposition (CBD) method to fabricate a p-ZnO/n-Si nanoscale heterojunction. The heterojunction exhibits typical rectifying current–voltage (I–V) curve with a turn-on voltage of 2.8 eV. The energy band diagrams of p-ZnO:(Ag,N)/n-Si and n-ZnO/n-Si heterojunctions were constructed to clarify the I–V characteristics. Both photoluminescence (PL) spectra and photocurrent spectra show strong ultraviolet (UV) emission peak of ZnO:(Ag,N) NRs. A high UV-to-visible rejection ratio at −2 V of 1.7 × 102 is observed from the photocurrent spectra. It indicates the p-ZnO:(Ag,N) NRs/n-Si heterojunction is a potential candidate for UV photodetector applications.