Growth and characterization of aluminum nitride, indium nitride, aluminum indium nitride semiconductors films and nanostructures.

摘要

The present research involving III-nitride (Al1-xIn xN (0 ≤ x ≤ 1) films has been motivated by their various potential microelectronic and optoelectronic applications. However, the progress toward these goals is impeded by technological difficulties of the AlN, InN and Al 1-xInxN film growth.; We have investigated pseudomorphic epitaxial growth of Al1-x InxN (0 ≤ x ≤ 1) films and self organized nanostructures on sapphire substrates using PSMBE deposition. The development of PSMBE technology including hollow cathode source design has been presented. We have demonstrated that the PSMBE growth technique is a very versatile and suitable to fabricate III-nitride films, especially AlN films, on various substrates with commercial applicability. Self-assembled InAlN nanostructures have been grown successfully on AlN/Sapphire by PSMBE. The small size of these grown nanostructures together with the uniformity of their size and shape imply the fascinating possibility of using them as self-assembled quantum dots.; We have investigated the behavior of the optical fundamental bandgap Eg of InxAl1-xN in temperature range 70--700K and molar concentration (0 ≤ x ≤ 1) using optical absorption spectroscopy. Our work clearly demonstrated bandgap engineering from 1.4 eV (InN) to 6.13 eV (AlN). InN films grown by PSMBE have been investigated using Raman scattering and photoluminescence (PL). Our PL investigations shown, that the band gap of 1.4 eV for InN would be more acceptable for InN grown on sapphire with AlN buffer layer, and there are no evidence of dramatically changes E g with oxygen contamination for InN films. Typical PL spectra for InN show good correlation with the absorption edges.; The study of the physical properties of III-nitrides, particulary the true value of energy band gaps of AlN and InN, will be continued by investigating the optimum growth conditions and thus improving the quality of the films. The study of the physical properties of ternary alloys and nanostructures on their base can give us a key to fabricate optoelectronic devices. Overcoming the challenges of the growth of III-nitrides and thorough understanding of the material properties are very important for the development of the promising III-nitride based optoelectronic devices.