title: Hybrid density functional study of band alignment in ZnO-GaN and ZnO-(Ga(1-x)Zn(x))(N(1-x)O(x))-GaN heterostructures.
abstract: The band alignment in ZnO-GaN and related heterostructures is crucial for uses in solar harvesting technology. Here, we report our density functional calculations of the band alignment and optical properties of ZnO-GaN and ZnO-(Ga(1-x)Zn(x))(N(1-x)O(x))-GaN heterostructures using a Heyd-Scuseria-Ernzerhof (HSE) hybrid functional. We found that the conventional GGA functionals underestimate not only the band gap but also the band offset of these heterostructures. Using the hybrid functional calculations, we show that the (Ga(1-x)Zn(x))(N(1-x)O(x)) solid solution has a direct band gap of about 2.608 eV, in good agreement with the experimental data. More importantly, this solid solution forms type-II band alignment with the host materials. A GaN-(Ga(1-x)Zn(x))(N(1-x)O(x))-ZnO core-shell solar cell model is presented to improve the visible light absorption ability and carrier collection efficiency.
authors.affiliation: School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, China.
authors.forename: Zhenhai
authors.initials: Z
authors.lastname: Wang
authors.forename: Mingwen
authors.initials: M
authors.lastname: Zhao
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Xi
authors.forename: Xiujie
authors.initials: X
authors.lastname: He
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Liu
authors.forename: Shishen
authors.initials: S
authors.lastname: Yan