Band alignment between NiOx and nonpolar/semipolar GaN planes for selective-area-doped termination structure

• 作者: Ji-Yao Du Ji-Yu Zhou Xiao-Bo Li Tao-Fei Pu Liu-An Li Xin-Zhi Liu Jin-Ping Ao
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
• 页码范围: 665-670
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/abdb21

摘要

Band alignment between NiOx and nonpolar GaN plane and between NiOx and semipolar GaN plane are measured by x-ray photoelectron spectroscopy.They demonstrate that the maximum value of the valence band in the unintentional-doped a-plane,m-plane,and r-plane GaN are comparable to each other,which means that all the substrates are of n-type with similar background carrier concentrations.However,the band offset at the NiOx/GaN interface presents obvious crystalline plane dependency although they are coated with the same NiOx films.By fitting the Ga 3d spectrum obtained from the NiOx/GaN interface,we find that relatively high Ga-O content at the interface corresponds to a small band offset.On the one hand,the high Ga-O content on the GaN surface will change the growth mode of NiOx.On the other hand,the affinity difference between Ga and O forms a dipole which will introduce an extra energy band bending.