A highly stable, accurate and fast photo-response in visible region: Role of introducing Ta2O5 /MWCNTs heterostructures in photodetector

This work presents the development of a novel photodetector design that leverages the synergistic combination of tantalum pentoxide (Ta2O5) and multi-walled carbon nanotubes (MWCNTs) to achieve superior visible light detection performance. Ta2O5/MWCNT heterostructures were synthesized and comprehensively characterized using various techniques. Structural, morphological, and optical analyses confirmed the suitability of these heterostructures for the targeted application. Photoluminescence spectroscopy was further employed to meticulously assess defect levels, which play a crucial role in photodetector performance. The photodetectors were fabricated using pure Ta2O5, pure MWCNTs, and the synthesized Ta2O5/MWCNT heterostructures. When subjected to different illumination wavelengths and voltages, the Ta2O5/MWCNT devices demonstrated significantly enhanced visible light detection and photocurrent compared to their individual counterparts. The measured responsivity, detectivity, and quantum efficiency of the Ta2O5/MWCNT photodetectors were highly impressive, reaching 81 mA/W, 16.38 × 106 Jones and 15.5 %, respectively. Critically, the fabricated photodetectors exhibited exceptional stability with rapid response times, characterized by an 80-ms rise and recovery cycle. This fast response characteristic underscores the potential of Ta2O5/MWCNT photodetectors in applications demanding high-speed and precise optical signal detection, such as those found in the fields of optical communication, sensing, and imaging.