Temperature Dependence of Low-Frequency Noise Characteristics of NiO_x/-Ga₂O₃ p-n Heterojunction Diodes

Temperature dependence of the low-frequency electronic noise in NiOx/beta-Ga2O3 p-n heterojunction diodes is reported. The noise spectral density is of the 1/f-type near room temperature but shows signatures of Lorentzian components at elevated temperatures and at higher current levels (f is the frequency). It is observed that there is an intriguing non-monotonic dependence of the noise on temperature near T = 380 K. The Raman spectroscopy of the device structure suggests material changes, which results in reduced noise above this temperature. The normalized noise spectral density in such diodes is determined to be on the order of 10(-14) cm(2) Hz(-1) (f = 10 Hz) at 0.1 A cm(-2) current density. In terms of the noise level, NiOx/beta-Ga2O3 p-n diodes perform excellently for new technology and occupy an intermediate position among devices of various designs implemented with different ultra-wide-bandgap semiconductors. The obtained results are important for understanding the electronic properties of NiOx/beta-Ga2O3 heterojunctions and contribute to the development of noise spectroscopy as the quality assessment tool for new electronic materials and device technologies.