Growth of Nanostructured Amorphous InSb by Vacuum Thermal Evaporation

Abstract

It is demonstrated here that even the simple vacuum thermal evaporation using a low flux rate (1.5 × 10²² molecules/s) can lead to the growth of InSb dots in the range 4–20 nm on glass substrates. The TEM diffraction analysis indicates the amorphous phase of the dots. The size distribution of the dots was determined by TEM images. The energy gaps of these amorphous dots were determined by optical absorption measurements and were found to vary linearly with inverse square of the dot size. This behavior indicates the quantum confinement effect in amorphous InSb dots. This analysis yields the bulk value of energy gap E_g(bulk) = 0.17 eV for the amorphous phase of InSb and the reduced effective mass μ = 0.0143, almost same as those of crystalline phase available in the literature.

Keywords:

• Physical Vapor Deposition (PVD)
• TEM
• optical absorption
• III–V semiconductor
• amorphous quantum dot

5. Acknowledgment

The financial support of Department of Science & Technology (DST), India in the form of Research Project No. SR/S5/NM/91/2006 and LASTEC Research Project No. 0172/CARS-8/TMD/LASTEC at Delhi University for this work is gratefully acknowledged.