Electrical and Optical Properties of a Cu<sub>2</sub>O/β‐Ga<sub>2</sub>O<sub>3</sub> pn‐Junction
S. I. Khartsev, Anatolijs Šarakovskis, Līga Grīnberga, Mattias Hammar, N. Nordell, Anders Hallén
Abstract
A pn‐heterojunction is fabricated by depositing an n‐type β‐Ga 2 O 3 film by pulsed laser deposition (PLD) on c‐cut Al 2 O 3 . P‐type cuprous oxide films, Cu 2 O, are then deposited by PLD, as well as by radio frequency (RF) magnetron sputtering. It is concluded that hole injection is prohibited by a 3.26 eV valence band barrier, as measured by X‐ray photo‐electron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). Heterojunction diode structures are prepared on the front side and electrical measurements demonstrate a rectification ration of 8 orders of magnitude and an ideality factor close to 2, indicating interface recombination‐controlled forward current. The junction is also optically active and shows a very fast photo‐response to 275 nm UV light.