This work investigates the temperature dependence of the current-voltage (I-V) characteristics of n-ZnO∕p-GaN junction diodes. The n-ZnO films were deposited on top of the p-GaN by dc sputtering with subsequent annealings at 500, 600, 700, and 800°C for 60s. The Hall measurement and the x-ray diffraction pattern are measured to study the n-ZnO films. The temperature sensitivity coefficients of the I-V characterizations are obtained by different substrate temperatures (25, 50, 100, and 150°C) and the extracted values are 2.10, 1.93, 3.22, and 1.36mV∕°C in the forward bias and 8.7, 8.0, 4.6, and 2.3mV∕°C in the reverse bias, respectively. The fabricated n-ZnO∕p-GaN diode with ZnO annealing temperatures at 800°C demonstrates the lowest temperature dependence.
This work presents dc characteristics (gain and leakage current) of a GaN/InGaN/ZnO npn collector-up heterojunction bipolar transistor (HBT) measured at 300, 200, and 100 K. The GaN-based epilayers of HBT were grown by metallorganic chemical vapor deposition, and the n-ZnO film was then deposited on top of p-InGaN by sputtering. X-ray diffraction analysis demonstrates that annealing at 600°C for 60 s in ambient normalN2 improved the quality of the ZnO film. Moreover, this study shows that the current gains (β) from the Gummel plot increased as the temperature decreased because the leakage current of the collector current (InormalC) is not a strong function of temperature. However, gains (GCE) from the measured common-emitter current–voltage characteristics increased slightly as the temperature decreased due to a reduction in the recombination current coupled with lower injection efficiency. These preliminary results show the potential of fabricating GaN/InGaN/ZnO HBTs without dry etching to reach the p-GaN layer, as required in the emitter-up geometry.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.