Park Jeung Hun, Kim Richard S, Pozuelo Marta, Chung Choong-Heui
Department of Materials Science and Engineering, University of California Los Angeles, 410 Westwood Plaza, Los Angeles, California 90095, United States.
Opto Diode Corporation, 1260 Calle Suerte, Camarillo, California 93012, United States.
J Nanosci Nanotechnol. 2019 Apr 1;19(4):2285-2290. doi: 10.1166/jnn.2019.15977.
We report the effect of morphology and substrate of self-catalyzed indium phosphide (InP) nanostructures on phonon vibration modes. Using liquid indium as a catalyst, we grew self-catalyzed InP nanocones and nanopillars on single crystal substrates of InP(111)B, Si(111), and Si(100) via metal-organic chemical vapor epitaxy. Due to crystal symmetry breaking in one-dimensional nanostructure, longitudinal-optical (LO) and transverse-optical (TO) phonon modes are clearly resolved with the strong anisotropic behavior. Broadening and downshift of LO phonon modes are found to be sensitive to the morphology (i.e., aspect ratio and surface-to-volume ratio) and crystal structure (i.e., Wurtzite and Zinc Blende) of the as-grown nanostructures. This work demonstrated that Raman spectroscopy provides statistical insights on the quality of as-grown nanostructures (i.e., growth orientation, crystal structures, and the presence of structural defects) without destroying samples.
我们报道了自催化磷化铟（InP）纳米结构的形貌和衬底对声子振动模式的影响。以液态铟作为催化剂，我们通过金属有机化学气相外延法在InP(111)B、Si(111)和Si(100)的单晶衬底上生长了自催化InP纳米锥和纳米柱。由于一维纳米结构中晶体对称性的破坏，纵向光学（LO）和横向光学（TO）声子模式通过强烈的各向异性行为清晰地分辨出来。发现LO声子模式的展宽和下移对生长的纳米结构的形貌（即纵横比和表面体积比）和晶体结构（即纤锌矿和闪锌矿）敏感。这项工作表明，拉曼光谱无需破坏样品就能提供关于生长的纳米结构质量（即生长取向、晶体结构和结构缺陷的存在）的统计见解。
