John Philipp, Trampert Achim, Van Dinh Duc, Spallek Domenik, Lähnemann Jonas, Kaganer Vladimir M, Geelhaar Lutz, Brandt Oliver, Auzelle Thomas
Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany.
Nano Lett. 2024 May 29;24(21):6233-6239. doi: 10.1021/acs.nanolett.4c00659. Epub 2024 May 17.
We study the molecular beam epitaxy of rock-salt ScN on the wurtzite GaN(11̅00) surface. To this end, ScN is grown on freestanding GaN(11̅00) substrates and self-assembled GaN nanowires exhibiting (11̅00) sidewalls. On both substrates, ScN crystallizes twin-free thanks to a specific epitaxial relationship, namely ScN(110)[001]∥GaN(11̅00)[0001], providing a congruent, low-symmetry interface. The 13.1% uniaxial lattice mismatch occurring in this orientation mostly relaxes within the first few monolayers of growth by forming a near-coincidence site lattice, where 7 GaN planes coincide with 8 ScN planes, leaving the ScN surface nearly free of extended defects. Overgrowth of the ScN with GaN leads to a kinetic stabilization of the zinc blende phase, that rapidly develops wurtzite inclusions nucleating on {111} nanofacets, commonly observed during zinc blende GaN growth. Our ScN/GaN(11̅00) platform opens a new route for the epitaxy of twin-free metal-semiconductor heterostructures including closely lattice-matched GaN, ScN, HfN, and ZrN compounds.
我们研究了纤锌矿型 GaN(11̅00) 表面上岩盐结构 ScN 的分子束外延生长。为此，在独立的 GaN(11̅00) 衬底和具有 (11̅00) 侧壁的自组装 GaN 纳米线上生长 ScN。在这两种衬底上，由于特定的外延关系，即 ScN(110)[001]∥GaN(11̅00)[0001]，ScN 结晶时无孪晶，提供了一个全等的、低对称性的界面。在这个取向中出现的 13.1% 的单轴晶格失配在生长的最初几个单层内大部分通过形成近巧合点阵而弛豫，其中 7 个 GaN 平面与 8 个 ScN 平面重合，使得 ScN 表面几乎没有扩展缺陷。用 GaN 覆盖 ScN 会导致闪锌矿相的动力学稳定，闪锌矿相迅速发展出在 {111} 纳米面上形核的纤锌矿包裹体，这在闪锌矿型 GaN 生长过程中很常见。我们的 ScN/GaN(11̅00) 平台为无孪晶金属 - 半导体异质结构的外延开辟了一条新途径，这些异质结构包括晶格匹配紧密的 GaN、ScN、HfN 和 ZrN 化合物。
