Zero-bias photo-induced charge separation using built-in electric field at p-NiO/n-Ga2O3 heterojunction interface

L Leonid Chernyak (Department of Physics, University of Central Florida 1 , Orlando, Florida 32816,) G Gabriel Marciaga (Department of Physics, University of Central Florida 1 , Orlando, Florida 32816,) J Jian-Sian Li (Department of Chemical Engineering, University of Florida 1 , Gainesville, Florida 32611,) C Chao-Ching Chiang (Department of Chemical Engineering, University of Florida 1 , Gainesville, Florida 32611,) H Hsiao-Hsuan Wan (Department of Chemical Engineering, University of Florida 1 , Gainesville, Florida 32611,) F Fan Ren S Stephen J. Pearton (Department of Materials Science and Engineering, University of Florida 2 , Gainesville, Florida 32611,) Y You Seung Rim (Department of Semiconductor Systems Engineering and Convergence Engineering for Intelligent Drone, Sejong University 1 , Seoul 05006,) A Arie Ruzin (School of Electrical Engineering, Tel Aviv University 6 , Tel Aviv 69978,) A Alfons Schulte (Department of Physics, University of Central Florida 1 , Orlando, Florida 32816,)

Abstract

As a viable alternative to the challenging fabrication of robust β-Ga2O3 p–n homojunctions, this study investigates the variable-temperature photocurrent of p-NiO/n-Ga2O3 heterojunction photodiodes under zero-bias conditions. The device's built-in electric field is utilized to achieve efficient separation of non-equilibrium photogenerated carriers. To support the experimental findings, computer simulations of the electric field distribution at the heterointerface were performed and correlated with experimental current–voltage and capacitance–voltage measurements. The photocurrent measurements confirm the narrowing of the n-Ga2O3 bandgap with increasing temperature, consistent with predictions from the Varshni equation. The observed decrease in photocurrent amplitude at lower temperatures is attributed to bandgap widening, which results in a smaller number of non-equilibrium carriers generated by the excitation wavelength.

Article Details

Volume / Issue Vol. 138, Issue 20
Published November 28, 2025
ISSN 0021-8979
Publisher American Institute of Physics

Journal Info

Journal of Applied Physics

American Institute of Physics

ISSN: 0021-8979 Physical Sciences

Authors (10)

L

Leonid Chernyak

Department of Physics, University of Central Florida 1 , Orlando, Florida 32816,

G

Gabriel Marciaga

Department of Physics, University of Central Florida 1 , Orlando, Florida 32816,

J

Jian-Sian Li

Department of Chemical Engineering, University of Florida 1 , Gainesville, Florida 32611,

C

Chao-Ching Chiang

Department of Chemical Engineering, University of Florida 1 , Gainesville, Florida 32611,

H

Hsiao-Hsuan Wan

Department of Chemical Engineering, University of Florida 1 , Gainesville, Florida 32611,

F

Fan Ren

S

Stephen J. Pearton

Department of Materials Science and Engineering, University of Florida 2 , Gainesville, Florida 32611,

Y

You Seung Rim

Department of Semiconductor Systems Engineering and Convergence Engineering for Intelligent Drone, Sejong University 1 , Seoul 05006,

A

Arie Ruzin

School of Electrical Engineering, Tel Aviv University 6 , Tel Aviv 69978,

A

Alfons Schulte

Department of Physics, University of Central Florida 1 , Orlando, Florida 32816,