Highly responsive self-driven broadband hybrid photodetector with high detectivity and on/off ratio based on Hibiscus sabdariffa

Abstract

A Hibiscus sabdariffa (HBS)/n-Si hybrid photodetector was fabricated and it was observed that the device has a high rectification ratio of 10.2 × 104 in dark and superior photoresponse at different intensities of visible light in addition to UV and IR lights. The non-linear response to light intensity in visible light was attributed to phase change effects and the presence of traps, which are the result of the hibiscus sabdariffa’ response to light. The responsivity at 850 nm reaches 1.16 A W−1 (at V = −2.0 V) and a high specific detectivity of 2.0 × 1012 Jones (for self-driven mode) with an external quantum efficiency of 411% was obtained. In addition, in self-driven mode of UV and IR lights, the highest on/off ratio and NPDR values reached ∼105 and ∼109 W−1 levels, respectively. Moreover, HBS/n-Si hybrid broad-band photodetector showed long-term stability (40 days) without encapsulation both in the dark and under the light.