Low Dark Current GaN p-i-n Photodetectors With a Low-Temperature AlN Interlayer

Abstract

Abstract-GaN p-i-n ultraviolet (UV) photodetectors (PDs) with a low-temperature (LT)-AlN interlayer were proposed and fabricated. It was found that the dark current of such detectors is as small as 28pA even at a high reverse bias of 40 V. Although the high potential barrier at the AlN-GaN interface would slightly reduce the responsivity of PD under low reverse biases, the high UV-to-visible rejection ratio of the PD with an LT-AlN interlayer could be achieved under high reverse biases due to its very low dark current. The rejection ratio of the PD with the LT-AlN interlayer is as large as 735 at the reverse bias of 40 V.

Ultraviolet Photodetectors Using Transparent Gate AlGaN/GaN High Electron Mobility Transistor on Silicon Substrate

“…GaN based devices are a strong candidate for a UV photodetector, because the required wavelength for the UV photodetector can easily be controlled by changing the composition of group-III materials such as Ga, Al, and In. 1) In recent years, photo-response of p-i-n, [2][3][4][5] Schottky, [6][7][8][9][10][11] and metal-semiconductor-metal (MSM)-type with GaN based materials has been demonstrated as a UV photodetector. [12][13][14][15][16][17] In these types of photodetectors, the MSMtype device with a two-dimensional electron gas have been expected to achieve a high sensitivity due to their high speed electron velocity and strong confinement of electrons.…”

An Ultraviolet Sensor and Indicator Module Based on p–i–n Photodiodes

“…III-nitride material has a suitable large bandgap energy, high quantum efficiency and high electron mobility. Many types of AlGaInN-based photodetectors (PDs) have been fabricated and tested [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28]. Schottky barrier PDs have been commercialized by several companies, and the typical responsivities of this type of PD are 0.18, 0.13, and 0.06 A/W at 350, 300, and 254 nm, respectively [3].…”