Spray deposition of CdTe thin films using nanoparticle precursors

2020-03-30 09:35:18

films Step Deposition CdTe degrees

责任者: Schulz, DL;Pehnt, M;Curtis, CJ;Ginley, DS 单位: 来源出处: METASTABLE, MECHANICALLY ALLOYED AND NANOCRYSTALLINE MATERIALS, PTS 1 AND 2, v 225 1996, p 169- 174 摘要: In this submission we report the use of nanoparticle precursors for the deposition of CdTe thin films. Capped CdTe nanoparticles (diameter = 30-50 Angstrom) were prepared by injection of a mixture of Cd(CH3)(2), (n-C8H17)(3)PTe, and (n-C8H17)(3)P into (n-C8H17)(3)PO at elevated temperatures. These nanoparticles were characterized by X-ray diffraction (XRD), W-Visible spectroscopy (UV-Vis), transmission electron microscopy (TEM) and scanning TEM energy dispersive X-ray spectroscopy (STEM/EDS). CdTe thin film deposition was accomplished by forming a colloidal suspension of CdTe nanoparticles in a suitable organic solvent and then spraying the colloid onto SnO2-coated glass substrates at variable susceptor temperatures according to a one-step or two-step process. The one-step process yielded smooth and dense CdTe thin films using growth temperatures approximately 200 degrees C less than conventional spray pyrolysis approaches. CdTe films were characterized by XRD, atomic force microscopy (AFM), Auger electron spectroscopy (AES) and electron probe micro analysis (EPMA). An increase in crystallinity and average grain size as determined by XRD was noted as growth temperature was increased from 240 to 300 degrees C. This temperature dependence of film grain size was further confirmed by AFM with no remnant nanocrystalline morphological features detected. The films obtained by the two-step process showed a dependence of crystallinity on annealing temperature. Atomic compositions determined by AES and EPMA showed nearly stoichiometric Cd and Te for both one- (T-gr = 300 degrees C) and two-step (T-anneal greater than or equal to 400 degrees C) deposited films; however, C impurities, presumably from the capping agent, were also detected. 关键词: nanoparticle; CdTe; spray pyrolysis; spray deposition; thin film; SEMICONDUCTOR NANOCRYSTALS; NANOSTRUCTURE; TEMPERATURE; PARTICLES; CHEMISTRY; ENERGY CHEMISTRY; ENERGY