类石墨烯锗烯研究进展

Recent progress of graphene-like germanene

近年来,伴随石墨烯研究的深入开展,考虑到兼容半导体工业,构筑类石墨烯锗烯并探究其奇特电学性质已成为凝聚态物理领域的研究前沿.本文首先简要介绍了锗烯这一全新二维体系的理论研究进展,包括锗烯的几何结构、电子结构及其调控以及它们之间的关系.理论研究表明,因最近邻原子间距大,锗烯比硅烯更难构筑,实验上构筑锗烯颇具挑战性.针对这一问题,介绍了实验上制备锗烯的一些进展,重点介绍了金属表面外延制备锗烯,并对本征锗烯的制备及其在未来纳电子学器件的潜在应用做出了展望.

With tremendous progress of graphene and with the consideration of the compatibility with semiconductor industry,the construction of analogous two-dimensional crystalline systems-new two-dimensional honeycomb and layered materials composed of elements other than carbon, the group IV（Si, Ge） analogs of graphene and the investigation of their fascinated electronic properties have become the frontier topics of condensed matter physics. Theoretical calculation predicts that unlike the planar structure of graphene, the germanene has stable, two-dimensional, low-buckled, honeycomb structure similar to that of silicene, but has much higher spin-orbit band gap than silicene, which is certainly of crucial importance in future electronics. The influences of atomic structures and the buckling of the low-buckled geometry on local electronic structure of the fabricated germanene are also reviewed from the atomic point of view. As theoretical studies on germanene are rapidly increasing, now the major challenge in this field is the preparation of high-quality germanene. Compared with silicene, the germanene has larger Ge-Ge interatomic distance which can weaken the orbital overlaps, resulting in the big difficulty in constructing germanene. In this work we review the recent progress of experimental epitaxial growth of germanene on surfaces, with emphasis on metal surfaces. The growth of quasi-freestanding germanene and its potential applications in nanoelectronics in the future are also discussed.