MoTe2 is the least explored material in the Molybdenum-chalcogen family, which crystallizes in thermodynamically stable semiconducting 2H phase at \textless 500 C and 1T' metallic phase at higher temperatures. Molecular beam epitaxy (MBE) provides an unique opportunity to tackle the small electronegativity difference between Mo and Te while growing layer by layer away from thermodynamic equilibrium. For a few-layer MoTe2 grown at a moderate rate of $\sim$6 mins per monolayer under varied Te:Mo flux ratio and substrate temperature, the boundary between the 2 phases in MBE grown MoTe2 on CaF2 is characterized using Reflection high-energy electron diffraction (RHEED), Raman spectroscopy and X-ray photoemission spectroscopy (XPS). Grazing incidence X-ray diffraction (GI-XRD) reveals a grain size of $\sim$90 {\AA} and presence of twinned grains. XRD, transmission electron miscroscopy, RHEED, low energy electron diffraction along with lack of electrical conductivity modulation by field effect in MBE 2H-MoTe2 on GaAs (111) B show likelihood of excess Te incorporation in the films. Finally, thermal stability and air sensitivity of MBE 2H-MoTe2 is investigated by temperature dependent XRD and XPS, respectively.
翻译:在Molybdenenum-Charcalcent家族中,Mote2T2H级的热动力稳定半导2H级,在高温下,在无500C和1T'的金属级上,MoTe2是热温下,在热温动力平衡之外,通过层层与热动力平衡不同而生长,解决摩与特之间的微电子差异,分子光束显性(MBEE)提供了独特的机会,解决莫与特之间的微电子差异,同时在摩与特之间,MoTe2是探索最少的材料。对于在以下各种Te:通量比率和基温温温度下,以每单层每单层平均6美6美元的适度速率增长:通量比率和基温温度下,MBRRRRRR、MHE2增长的2阶段之间,MMO2MoT2阶段之间的边界界线是使用反射高能电电电解、光光谱和X光光光光光光光光光光分解(GXRMM-XRRRRRM、GMMRMRMRRR)最后在BRV、BRMRV、XRMRM-RV、XX的磁的磁的磁的低磁的磁的磁、BRVRV、BRMMMMF的磁的磁的磁的磁的磁、X-RVV、B-RV、X-RV、X-RMMMMMRV、XXX-RMLV的磁的磁的基、X-RM-RM的磁的磁的低、B的基、BRM-A-A-RVV的低、B-RVV的磁的基的低、B-A-A-RM的低、B-A-B-A-A-RV-R-A-RV-RMLV的低-RV-RM的低-RV、B-RV、X-RV、X-A-RV、X-A-RM-RM-A-A-A-RM-RM-A-A-A-RM-C-A-A的磁的磁的