Carbon-Nanotube/${\hat{I}}^2$-Ga${}_2$O${}_3$ Heterojunction PIN Diodes

Abstract

${\hat{I}}^2$-Ga${}_2$O${}_3$ is gaining attention as a promising semiconductor for next-generation high-power, high-efficiency, and high-temperature electronic devices, thanks to its exceptional material properties. However, challenges such as the lack of viable p-type doping have hindered its full potential, particularly in the development of ambipolar devices. This work introduces a novel heterojunction diode (HD) that combines p-type carbon nanotubes (CNTs) with i/n-type ${\hat{I}}^2$-Ga${}_2$O${}_3$ to overcome these limitations. For the first time, a CNT/${\hat{I}}^2$-Ga${}_2$O${}_3$ hetero-p-n-junction diode is fabricated. Compared to a traditional Schottky barrier diode (SBD) with the same ${\hat{I}}^2$-Ga${}_2$O${}_3$ epilayer, the CNT/${\hat{I}}^2$-Ga${}_2$O${}_3$ HD demonstrates significant improvements, including a higher rectifying ratio ($1.2\times 10^{11}$), a larger turn-on voltage (1.96 V), a drastically reduced leakage current at temperatures up to 300 °C, and a 26.7% increase in breakdown voltage. Notably, the CNT/${\hat{I}}^2$-Ga${}_2$O${}_3$ HD exhibits a low ideality factor of 1.02, signifying an ideal interface between the materials. These results underline the potential of CNT/${\hat{I}}^2$-Ga${}_2$O${}_3$ heterojunctions for electronic applications, offering a promising solution to current limitations in ${\hat{I}}^2$-Ga${}_2$O${}_3$-based devices.

17 pages, 5 figures