Demonstration of Spectral Selectivity of Efficient and Ultrafast GaN/AlGaN-Based Metal–Semiconductor–Metal Ultraviolet Photodiodes

Abstract

Efficient and ultrafast (aluminum)-galliumnitride-based metal-semiconductor-metal (Alx)Ga1-xN ultraviolet photodiodes were implemented to investigate the spectral properties of GaN/AlGaN-based photodetectors. Al composition of the GaN templates were varied from 0-% to 30% to demonstrate the impact of Al mole fraction on the cutoff wavelength of these UV photodiodes. Asymmetric metal contact electrodes were fabricated to optimize the external quantum efficiency without compromising their ultrafast photoresponse. The best performing devices exhibited a peak response of 4 V and an oscilloscope limited temporal pulse width of 61 ps at a 20-V bias with a peak spectral responsivity of 36.5 mA/W at 280 nm.

Metal-semiconductor-metal structured p-i-n GaN/AlGaN ultrafast detectors for deep-UV photodetection

“…This paper discusses the preliminary results that we obtained from the design, fabrication, and characterization of this novel category of AlGaN/GaN-based ultrafast, sensitive photodiodes for solar blind UV sensing. The optimal device yielded a peak responsivity of 3.5 A/W under 262-nm illumination with full width half maximum of 337.2-ps and 37.5-ps rise times when biased with 20 V. The outcomes of this investigation suggest that it is possible to bypass the bottlenecks associated with the formation of Schottky contacts [3][4][5][6][7] on conventional metal−semiconductor-metal photodiodes based on AlGaN/GaN templates.…”

“…Finally, the parasitic effects of the coupling circuit could introduce some ringing in the response pulse of the PD under characterization. Previous laterally oriented MSM devices mounted on the same circuit, however, did not exhibit this level of ringing [2,7], so the QW complex carrier dynamics contributed significantly to the ringing [10]. The results of the influence of bias voltage on the rise time and pulse width of the Pt p-i-n configured MSM photodetector are plotted in Fig.…”

Broadband Photodetector for Ultraviolet to Visible Wavelengths Based on the BA2PbI4/GaN Heterostructure

“…Thus, to conquer the narrow-band response problem of perovskites, an effective approach is to integrate the sample with a suitable wide-band-gap semiconductor to broaden the response spectra. Compared with other III-nitrides, GaN-based materials have attracted increasing attention owing to the advantages of a wide band gap, strong chemical stability, and a tunable band gap (3.4–6.2 eV). , Various PD device structures based on GaN materials can be divided into p–n junction diodes, p–i–n diodes, Schottky barrier PDs, and metal–semiconductor–metal (MSM) PDs . Among them, p–n junction PDs are an ideal choice for practical applications owing to their sharp cutoff, high responsivity, and fast response speed.…”