Structural and optical properties of nanocube Al1-xInxSb thin films deposited by thermal evaporation technique

Abstract

Al1-xInxSb (x=0.0, 0.1, and 0.2) thin films were deposited on glass substrates at room temperature in vacuum by thermal evaporation technique. The morphology, structure and optical properties of the Al1-xInxSb thin films were characterized using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), UV-vis spectrophotometer, and photoluminescence (PL) spectroscopy. FESEM revealed the formation of nanocubes morphology, and XRD showed the cubic structure of the Al1-xInxSb thin films. According to the AFM analysis we can remark that high average surface roughness (RMS) value of Al1-xInxSb nanocubes thin film obtained with In-doped concentrations equal to x = 0.2, is about of 141 nm. From UV–vis absorption spectra, the direct energy gap values for the samples with x=0.0, 0.1, and 0.2 were 2.7 eV, 2.5 eV, and 2.4 eV, respectively. The PL spectra obtained indicated strong green shifts at 530 nm, 535 nm, and 560 nm with intensities gradually increasing with increasing x fraction. The Raman scattering spectra may be attributed to the bonding behaviors of Sb–LO mode for bulk AlSb crystals. These results reveal the quantum confinement of the Alx-1InxSb nanocubes.