Energy band alignment at Cu2O/ZnO heterojunctions characterized by in situ x-ray photoelectron spectroscopy

• 来源期刊: 中国物理B（英文版）
• 关键词: Cu2O ZnO x-ray photoelectron spectroscopy laser-molecular beam epitaxy
• 年，卷（期）: 2019,（8）
• 页码范围: 311-315
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/1674-1056/28/8/087301

摘要

With the increasing interest in Cu2O-based devices for photovoltaic applications,the energy band alignment at the Cu2O/ZnO heterojunction has received more and more attention.In this work,a high-quality Cu2O/ZnO heterojunction is fabricated on a c-Al2O3 substrate by laser-molecular beam epitaxy,and the energy band alignment is determined by x-ray photoelectron spectroscopy.The valence band of ZnO is found to be 1.97 eV below that of Cu2O.A type-Ⅱ band alignment exists at the Cu2O/ZnO heterojunction with a resulting conduction band offset of 0.77 eV,which is especially favorable for enhancing the efficiency of Cu2O/ZnO solar cells.