High-performance self-powered broadband photodetector based on AgxOy@n-Si heterojunction

Thin silver oxide AgxOy film (p-type) was deposited via DC magnetron sputtering onto n-type silicon substrate and integrated into a pn heterojunction architecture. Structural (XRD, XPS and EDX), optical ultraviolet-visible-near infrared and morphological analysis (SEM) of the AgxOy film were investigated in detail. Electrical measurements revealed that the AgxOy/n-Si pn heterojunction as a self-driven photodetector device exhibits a high photoresponse both in visible light and in UV, IR and yellow lights. It was also observed that under visible light the photocurrent increased with increasing light intensity, higher at higher intensities. Furthermore, the photodetector exhibits high sensitivity to the incident light of 365 nm with responsivity as 1061 mA W−1 for −1.5 V. The highest specific detectivity value for the conditions illuminated by LED with wavelength of 590 nm is 9.77 × 1012 cm·Hz1/2·W−1 (Jones) for zero bias. Experimental results show that the AgxOy/n-Si heterojunction has great potential for practical applications as self-driven and high-performance photodetectors.