GaN heterostructures for next generation of highly robust RF power electronics: from growth design to devices

We report on a novel ultrathin high polarization AlN/GaN heterostructure for millimeter-wave applications that allows achieving unique combination of high performance and high robustness. A key feature has been the implementation of a thick in-situ SiN cap layer. A full description from growth design to major electrical data with respect to device reliability will be provided in the presentation

Excitation intensity and temperature-dependent performance of ingan/gan multiple quantum wells photodetectors

In this article, we investigate the behavior of InGaN\u2013GaN Multiple Quantum Well (MQW) photodetectors under different excitation density (616 \ub5W/cm2 to 7.02 W/cm2) and temperature conditions (from 25\u25e6C to 65\u25e6C), relating the experimental results to carrier recombination/escape dynamics. We analyzed the optical-to-electrical power conversion efficiency of the devices as a function of excitation intensity and temperature, demonstrating that: (a) at low excitation densities, there is a lowering in the optical-to-electrical conversion efficiency and in the short-circuit current with increasing temperature; (b) the same quantities increase with increasing temperature when using high excitation power. Moreover, (c) we observed an increase in the signal of photocurrent measurements at sub-bandgap excitation wavelengths with increasing temperature. The observed behavior is explained by considering the interplay between Shockley\u2013Read\u2013Hall (SRH) recombination and carrier escape. The first mechanism is relevant at low excitation densities and increases with temperature, thus lowering the efficiency; the latter is important at high excitation densities, when the effective barrier height is reduced. We developed a model for reproducing the variation of JSC with temperature; through this model, we calculated the effective barrier height for carrier escape, and demonstrated a lowering of this barrier with increasing temperature, that can explain the increase in short-circuit current at high excitation densities. In addition, we extracted the energy position of the defects responsible for SRH recombination, which are located 0.33 eV far from midgap

Carrier generation and recombination dynamics and reliability of InGaN-based photodetectors for high power densities

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Degradation processes and origin in InGaN-based high-power photodetectors

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Photon-driven degradation processes in GaN-based optoelectronic devices

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