Investigation of a minority carrier trap in a NiO/β-Ga₂O₃ p–n heterojunction via deep-level transient spectroscopy

Abstract

Properties of a minority carrier (hole) trap in β-Ga2O3 have been explicitly investigated using a NiO/β-Ga2O3 p-n heterojunction. By deep level transient spectroscopy (DLTS), activation energy for emission (Eemi ) and hole capture cross section (σp ) were derived to be 0.1 eV and 2.48×10-15 cm2, respectively. Temperature-enhanced capture and emission kinetics were revealed by the decrease of capture time constant (τc ) and emission time constant (τe ). Moreover, it was determined that emission process of the minority carrier trap is electric-field-independent. Taking carrier recombination into account, corrected trap concentration (NTa ) of 2.73×1015 cm-3 was extracted, together with electron capture cross section (σn ) of 1.42×10-18 cm2. This study provides a foundation for comprehending trap properties in β-Ga2O3, which is crucial to overcoming self-trapped hole (STH) effects in obtaining p-type β-Ga2O3 materials and performance enhancement of β-Ga2O3-based power devices.