AlGaN-based high-performance metal–semiconductor–metal photodetectors

Abstract

Design, structure growth, fabrication, and characterization of high performance AlGaN-based metal-semiconductor-metal (MSM) photodetectors (PD) are reported. By incorporating AlN nucleation and buffer layers, the leakage current density of GaN MSM PD was reduced to 1.96 Â 10 À10 A/cm 2 at a 50 V bias, which is four orders of magnitude lower compared to control devices. A 229 nm cutoff wavelength, a peak responsivity of 0.53 A/W at 222 nm, and seven orders of magnitude visible rejection was obtained from Al 0.75 Ga 0.25 N MSM PD. Two-color monolithic AlGaN MSM PD with excellent dark current characteristics were demonstrated, where both detectors reject the other detector spectral band with more than three orders of magnitude. High-speed measurements of Al 0.38 Ga 0.62 N MSM PD resulted in fast responses with greater than gigahertz bandwidths, where the fastest devices had a 3-dB bandwidth of 5.4 GHz.

Progress on AlGaN-based solar-blind ultraviolet photodetectors and focal plane arrays

“…To improve the crystalline quality of high-Al-content AlGaN epitaxial thin films, researchers have tried various methods to control stress to reduce the dislocations during the material growth process. Mudu et al 103 incorporated a low temperature (840 °C) AlN nucleation layer onto the c-plane sapphire substrate. Subsequently, an AlN buffer layer grown at high temperature (1150 °C) is employed to convert the island-like three-dimensional growth mode at low temperatures into a two-dimensional growth mode.…”

Deep-ultraviolet integrated photonic and optoelectronic devices: A prospect of the hybridization of group III–nitrides, III–oxides, and two-dimensional materials

“…Up until now, no solution has been found to address high defect densities associated with the incorporation of Al x Ga 1−x N layers with high aluminum contents. Walker et al was one of the earliest to demonstrate Al x Ga 1−x N-based PDs operating in DUV wavelengths with a responsivity of 0.11 A/W at 232 nm (5 V reverse voltage) and an IQE of 90% [536] . In their device structure, high-aluminum-content Al x Ga 1−x N layers of up to x = 70% were successfully grown using low-pressure chemical vapor deposition (LPCVD) on sapphire substrates.…”

ZnO Metal-Semiconductor-Metal UV Photodetectors on PPC Plastic with Various Metal Contacts

“…ZnSe-based UV photodetectors, which is another wide direct band gap material, have also been manufactured (Hanzaz et al, 2007). Fabrication and characterization of low-intensity ultraviolet metal-semiconductor-metal (MSM) photodetectors based on AlGaN have also been reported (Gökkavas et al, 2007). ZnO is another semiconductor of wide direct bandgap that is also sensitive in the UV region and is of low cost and easy to manufacture.…”