Highly stable, self-powered UV-Vis-NIR broadband isotype photodetector based on Ti-doped amorphous MoO 3

Ti -doped MoO 3 thin film was sputtered onto a n -Si substrate and the MoO 3 :Ti/n-Si heterojunction photodetector fabricated. The elemental composition and the morphological analyses of the MoO 3 film have been carried out by EDX and SEM studies, respectively. The band gap of sputtered MoO 3 :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 MoO 3 :Ti/n-Si heterojunction photodetector, the largest responsivity values were determined as 0.41 A/W in visible light of 10 mW/cm 2 , 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 x10 9 Jones in visible light (10 mW/cm 2 ), 1.61 x10 10 Jones, under UV light of 365 nm, and 3.21 x10 9 Jones, respectively. Repeated measurements after 30 days showed that the device was quite stable both in the dark and in a broadband.