High-Speed and High-Responsivity Blue Light Photodetector with an InGaN NR/PEDOT:PSS Heterojunction Decorated with Ag NWs.

ABSTRACT

InGaN nanorods possessing larger and wavelength selective absorption by regulating In component based visible light photodetectors (PDs) as one of the key components in the field of visible light communication have received widespread attention. Currently, the weak photoelectric conversion efficiency and slow photoresponse speed of InGaN nanorod (NR) based PDs due to high surface states of InGaN NRs impede the actualization of high-responsivity and high-speed blue light PDs. Here, we have demonstrated high-performance InGaN NR/PEDOTPSS@Ag nanowire (NW) heterojunction blue light photodetectors utilizing surface passivation and a localized surface plasmon resonance effect. The dark current is significantly reduced by passivating the InGaN NR surface states using PEDOTPSS. The photoelectric conversion efficiency is significantly increased by increasing light absorption due to the electromagnetic field oscillation of Ag NWs. The responsivity, external quantum efficiency, detectivity, and fall/off time of the InGaN NR/PEDOTPSS@Ag NW PDs are up to 2.9 A/W, 856%, 6.64 × 1010 Jones, and 439/725 µs, respectively, under 1 V bias and 420 nm illumination. The proposed device design presents a novel approach toward the development of low-cost, high-responsivity, high-speed blue light photodetectors for applications involving visible light communication.