School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, China.
Phys Chem Chem Phys. 2012 Dec 5;14(45):15693-8. doi: 10.1039/c2cp42115a. Epub 2012 Oct 22.
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.
在 ZnO-GaN 和相关异质结构中，能带排列对于太阳能收集技术的应用至关重要。在这里，我们使用 HSE 杂化泛函报告了 ZnO-GaN 和 ZnO-(Ga(1-x)Zn(x))(N(1-x)O(x))-GaN 异质结构的能带排列和光学性质的密度泛函计算。我们发现，传统的 GGA 泛函不仅低估了这些异质结构的能带隙，而且还低估了能带偏移。通过使用杂化泛函计算，我们表明（Ga(1-x)Zn(x))(N(1-x)O(x))固溶体具有约 2.608 eV 的直接带隙，与实验数据吻合较好。更重要的是，这种固溶体与宿主材料形成了 II 型能带排列。提出了 GaN-(Ga(1-x)Zn(x))(N(1-x)O(x))-ZnO 核壳太阳能电池模型，以提高可见光吸收能力和载流子收集效率。
