Formation and stability of point defects in monolayer rhenium disulfide
Formation and stability of point defects in monolayer rhenium disulfide
复制标题
DOI：
10.1103/physrevb.89.155433
复制
发表时间：
2014-04-28
影响因子：
3.7
通讯作者：
Peeters, F. M.
中科院分区：
文献类型：
--
作者：
Horzum, S.;Cakir, D.;Peeters, F. M.
最近，实验上用传统的机械剥离技术从生长的ReS 2晶体中提取了二硫化铼（ReS 2）单分子膜。与众所周知的过渡金属二硫属化物（TMD）不同，ReS 2以稳定的扭曲-1T结构结晶，缺乏间接到直接的间隙交叉。在这里，我们提出了一个实验和理论研究的形成，能量学和稳定性的最突出的晶格缺陷在单层ReS 2。在实验上，用3-MeV He+2离子照射来打破ReS 2薄片中的强共价键。光致发光的测量结果表明，从单分子膜的发光大部分是不变的高能粒子照射后。为了了解ReS 2中可能的空位的能量学，我们进行了系统的第一性原理计算。我们的计算表明，形成一个单一的硫空位具有最低的形成能在Re和S丰富的条件和随机分布的这种缺陷是积极更可取的。硫点缺陷不导致任何自旋极化，而含Re点缺陷的产生诱导具有1-3 μ B的净磁矩的磁化。实验观察到的容易形成的硫空位是在很好的协议与第一性原理计算。
Recently, rhenium disulfide (ReS2) monolayers were experimentally extracted by conventional mechanical exfoliation technique from as-grown ReS2 crystals. Unlike the well-known members of transition metal dichalcogenides (TMDs), ReS2 crystallizes in a stable distorted-1T structure and lacks an indirect to direct gap crossover. Here we present an experimental and theoretical study of the formation, energetics, and stability of the most prominent lattice defects in monolayer ReS2. Experimentally, irradiation with 3-MeV He+2 ions was used to break the strong covalent bonds in ReS2 flakes. Photoluminescence measurements showed that the luminescence from monolayers is mostly unchanged after highly energetic a particle irradiation. In order to understand the energetics of possible vacancies in ReS2 we performed systematic first-principles calculations. Our calculations revealed that the formation of a single sulfur vacancy has the lowest formation energy in both Re and S rich conditions and a random distribution of such defects are energetically more preferable. Sulfur point defects do not result in any spin polarization whereas the creation of Re-containing point defects induce magnetization with a net magnetic moment of 1-3 mu B. Experimentally observed easy formation of sulfur vacancies is in good agreement with first-principles calculations.