Epitaxial Integration and Defect Structure of Layered SnSe Films on PbSe/III–V Substrates
Epitaxial Integration and Defect Structure of Layered SnSe Films on PbSe/III–V Substrates
复制标题
DOI：
10.1021/acs.cgd.2c00188
复制
发表时间：
2022-05
期刊：
影响因子：
--
通讯作者：
Brian B. Haidet;E. Hughes;K. Mukherjee
中科院分区：
文献类型：
--
作者：
Brian B. Haidet;E. Hughes;K. Mukherjee
我们通过分子束外延在III-V族衬底上合成了SnSe（一种货车van der Waals（vdW）层状半导体）外延薄膜。虽然SnSe在GaAs（001）表面上的直接沉积导致多晶生长，但是扭曲的岩盐SnSe和岩盐PbSe中间层之间的结构相似性促进了SnSe的有序准vdW外延，其中仅具有由较低的膜对称性引起的离散面内旋转。朝向操纵分层的SnSe的改进的机械，光电，和铁弹/铁电性能，我们表明，SnSe/PbSe-上-III-V接口是结构相称和化学相容的足够的通道的子单元格表面步骤和线程位错与部分伯格斯矢量到层状晶格从3D模板。这样的界面和扩展的缺陷导致在SnSe中的新颖堆叠沿着，具有跨vdW间隙交联层和产生混合维度的膜的潜力。我们评估的前景的热膨胀失配救济通过滑动vdW接口在3D/层状/3D键合异质结构使用PbSe/SnSe/PbSe-on-InAs，并发现这是无效的对开裂的位错扩散，晶界，和交联缺陷脆化的异质结构。
We synthesize epitaxial films of SnSe, a van der Waals (vdW) layered semiconductor, on III–V substrates via molecular beam epitaxy. While direct deposition of SnSe on GaAs(001) surfaces results in polycrystalline growth, the structural similarity between the distorted rocksalt SnSe and a rocksalt PbSe interlayer facilitates ordered quasi-vdW epitaxy of SnSe with only discrete in-plane rotations arising from the lower film symmetry. Toward manipulating the layering of SnSe for improved mechanical, optoelectronic, and ferroelastic/ferroelectric properties, we show that SnSe/PbSe-on-III–V interfaces are structurally commensurate and chemically compatible enough for the passage of sub-unit-cell surface steps and threading dislocations with partial Burgers vectors into the layered lattice from the 3D template. Such interfaces and extended defects result in novel stacking in SnSe along with the potential to crosslink layers across the vdW gap and yield films of mixed dimensionality. We assess the prospect of thermal expansion mismatch relief via sliding vdW interfaces in a 3D/layered/3D-bonded heterostructure using PbSe/SnSe/PbSe-on-InAs and find this to be ineffective against cracking as dislocation diffusion, grain boundaries, and crosslinking defects embrittle the heterostructure.