Investigating visible range photoresponse of organic single-crystal of green fluorescent protein analogue

Abstract

The growing demand for lightweight, flexible, semi-transparent and low-cost photodetectors (PDs) in wearable electronics and optical communication systems has promoted studies to investigate organic materials as feasible alternatives to conventional inorganic PDs. However, modern organic PDs often demonstrate responsivity, detectivity, and photoresponse speed limitations, particularly in the visible range. Here, we report the photoresponse of the organic single-crystal analogue of the Green Fluorescent Protein (GFP) chromophore photodetector device fabricated on silicon nitride substrates. A significant rise in photocurrent was reported under the illumination of visible wavelengths (532 nm, 630 nm, and Halogen light). The observed photoresponse is remarkably convincing and repetitive during ON/OFF cycles of laser light illumination. The voltage dependence of photocurrent is noticed for the device. The photocurrent, rise & decay times, responsivity, detectivity, noise equivalent power and external quantum efficiency are studied for different wavelengths. Strikingly, the fabricated device demonstrates excellent performance in the visible region compared to several conventional organic and inorganic PDs. The responsivity and detectivity are observed to be as large as 98mA/W and 7.94 x 108 Jones respectively. Furthermore, the device demonstrates fast photoresponse dynamics with a rise time of 180 ms and a decay time of 152 ms. The high-performing photodetection properties indicated that the Single-crystal GFP analogue could be used as a broadband material for future optoelectronic applications.