TÍNH CHẤT QUANG CỦA MÀNGMỎNGInSb TRÊN ĐẾ c-SAPPHIRE ĐƯỢC CHẾ TẠO BẰNG PHƯƠNG PHÁP LẮNG ĐỌNG LASER XUNG

Abstract

1 μm-InSbcrystallizedthin films were successfully deposited based on Pulsed Laser Deposition (PLD) approach, and later characterized. XRD analysis reveals that the InSb films with Sb in excess are constituted by a wide range of various nanocrystals, of which the sizes are from 148 nm to 322 nm corresponding to different depositedtemperatures (Td) ranging from 250°C to 400°C. While films show polycrystalline properties at low Td(< 400°C), nearly single crystallized films have been achieved at higher Tdwith space group structure of Zinc Blende. Microstructural analysis performed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) agrees with results obtained from XRD and suggests that microstructure is transformed from small grains in size to bigger ones with increasing Td. In addition, Raman scattering spectroscopy illustrates that the fabricated films have a variety modes of vibration, which can be 2TA, TO-TA, Sb-Sb, TO, and LO depending on the sample Td. By means of Fourier transform infrared (FTIR) measurement, adecrease in the band-gap energy of deposited films is observed with increasing Td.