Highly stable, self-powered UV-Vis-NIR broadband isotype photodetector based on Ti-doped amorphous MoO3

Ti-doped MoO3 thin film was sputtered onto a n-Si substrate and the MoO3:Ti/n-Si heterojunction photodetector fabricated. The elemental composition and the morphological analyses of the MoO3 film have been carried out by EDX and SEM studies, respectively. The band gap of sputtered MoO3:Ti film was found to be 3.26 eV from UV-Vis spectra. The optical performance of the constructed device under visible light between 10 and 150 mW, under 365 nm and 395 nm UV light and 850 nm NIR light was examined in detail with the help of current-voltage (I-V) characteristics. From the analysis of the experimental I-V characteristics of the MoO3:Ti/n-Si heterojunction photodetector, the largest responsivity values were determined as 0.41 A/W in visible light of 10 mW/cm2, 2.03 A/W under UV light of 365 nm and 0.67 A/W for 850 nm NIR light, respectively. Furthermore, the largest specific detectivity values were calculated as 3.21×109 Jones in visible light (10 mW/cm2), 1.61×1010 Jones, under UV light of 365 nm, and 3.21×109 Jones, respectively. Repeated measurements after 30 days showed that the device was quite stable both in the dark and in a broadband.