Abstract
Transparent oxide semiconductors hold great promise for many optoelectronic devices such as transparent electronics, UV-emitting devices, and photodetectors. A p-n heterojunction is the most ubiquitous building block to realize these devices. In this work, we report the fabrication and characterization of the interface properties of a transparent heterojunction consisting of p-type NiO and n-type perovskite BaSnO3. We show that high-quality NiO thin films can be epitaxially grown on BaSnO3 with sharp interfaces because of a small lattice mismatch (∼1.3%). The diode fabricated from this heterojunction exhibits rectifying behavior with a ratio of 500. X-ray photoelectron spectroscopy reveals a type II or "staggered" band alignment with valence and conduction band offsets of 1.44 eV and 1.86 eV, respectively. Moreover, a large upward band bending potential of 0.90 eV for BaSnO3 and a downward band bending potential of 0.15 eV for NiO were observed in the interface region. Such electronic properties have important implication for optoelectronic applications as the large built-in potential provides favorable energetics for photo-generated electron-hole separation/migration.
Original language | English |
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Article number | 171605 |
Journal | Applied Physics Letters |
Volume | 112 |
Issue number | 17 |
DOIs | |
Publication status | Published - 23 Apr 2018 |
Funding
K.H.L. Zhang is grateful for funding support from the Thousand Youth Talents Program of China and Herchel Smith Postdoctoral Fellowship by the University of Cambridge. S. Han, S. Xiang, J. Zou, and M. Gu were supported by the Pico Center at SUSTech that receives support from Presidential fund and Development and Reform Commission of Shenzhen Municipality.