应变对GaN基半导体异质结构输运和自旋性质的影响

GaN-based semiconductor is a new low-dimensional semiconductor material system with large band offset, strong polarization-induced electric field, long spin coherence time and high Curie temperature. It has significant applications in high temperature, high power and high frequency electronic devices and is a very promising candidate for future spintronic application. This program studies the transport and spin properties under strain and stress by means of the magnetoresistance measurements and circular photogalvanic effect measurements, aiming at developing GaN based electronic and spintronic devices. The main contents include: the MOCVD growth of the high quality GaN-based heterostructures; the transport and spin properties of the two-dimensional electron gas under strain and stress, etc. The applicant of the program as well as the research team is engaged in the research of this field for many years, obtained a lot of achivements and gathered some research experiences. The objectives and contents of the program are advanced in the fields of low-dimensional semiconductor physics and spintronics.

GaN基半导体异质结构具有很大的能带偏移，很强的自发和压电极化，较长的自旋驰豫时间和高于室温的居里温度，是发展高温高频高功率电子器件和自旋电子学器件的优选材料。本申请项目根据当前国际上半导体低维物理和宽禁带半导体材料、器件研究的发展趋势，以探索强极化体系GaN基材料中的物理性质和变化规律、发展GaN基半导体异质结构器件为目标，以强磁场、超低温磁阻测量和自旋光电流测量为主要测量手段，利用流体静压力和单轴应力装置开展应力和应变下GaN基半导体材料的输运和自旋性质研究，内容涉及高质量GaN基异质结构材料的金属有机化学气相淀积生长和材料微结构表征，强应力和应变、强极化电场下二维电子气的输运性质和本征自旋性质等。本项目申请人及所在的课题组近年来一直从事与该领域相关的研究工作，取得了一批富有特色的研究成果并积累了经验。本项目的研究目标和内容均处于当前国际上半导体低维物理和半导体自旋电子学的前沿领域。

四年来，经过课题组成员的不懈努力，我们在高质量GaN基异质结构材料的MOCVD外延生长、大应变强极化条件下GaN基异质结构材料的能带、输运和自旋性质及其调控规律等方面开展了系统的研究工作，并拓展到谷电子学研究，取得了若干重要进展。四年来共发表SCI收录论文15篇，包括Science advances 论文1篇、Nano Letters论文2篇、其它影响因子大于3的文章10篇。在国际学术会议上做邀请报告1次，在国内学术会议上做邀请报告5次。 4年来共有1人获得优青，毕业博士研究生3人、硕士研究生3人。参与承办大型国际学术会议1次和国内学术会议1次。圆满完成了计划任务书规定的各项研究任务。