Growth and properties of InN, InGaN, and InN/InGaN quantum wells
|Yasushi Nanishi 1, Hiroyuki Naoi 2, Tsutomu Araki 3, Masahito Kurouchi 4, Daisuke Muto 5, Takao Miyajima 6|
1. Department of Photonics, Ritsumeikan University, Kusatsu 525-8577, Japan
InN and related alloys are very attractive materials for future photonic and electronic devices. Extensive studies on InN and In-rich InxGa1-xN have been hindered for a long time by the difficulties of growing high-quality crystals because of high vapor pressure of nitrogen and low dissociation temperature. Recent developments of high-quality InN by MOVPE and MBE, coupled with discussion on true band-gap energy of InN, revived extensive attentions on this material system.
We already reported high-quality InN growth by RF-MBE. Comprehensive characterization of the grown films using XRD, TEM, EXAFS and Raman scattering clearly demonstrated that InN films grown in this study had ideal hexagonal wurtzite structure. We also reported successful growth of InxGa1-xN films in full compositional range without noticeable phase separation.
In this presentation, we will report on our recent developments of InN and InxGa1-xN growth. We have found that the insertion of a high-temperature-grown InN layer as a growth template was very effective for improving the surface morphology and crystalline quality of In-rich InxGa1-xN layers. We have also succeeded in dramatically improving the crystalline quality of InN films by optimizing nitridation conditions of (0001) sapphire substrates. These high-quality InN films showed their excellent c-axis orientation with the FWHMs of (0002) XRCs as narrow as 1 arcmin without deteriorating their a-axis orientation. By using these high-quality InN layers as growth templates, the crystalline quality of In0.8Ga0.2N layers was dramatically improved. Based on these studies, an InN/In0.8Ga0.2N multiple quantum well structure and InN/In0.8Ga0.2N single quantum well structures with various well widths were successfully grown on these high-quality InN templates. The MQW structure showed clear 1st and 2nd satellite peaks of XRD. The SQW structures exhibited photoluminescence emission from their well layers.
[ABSTRACT TRUNCATED TO 2000 LETTERS]
Presentation: invited oral at E-MRS Fall Meeting 2005, Symposium A, by Hiroyuki Naoi
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-05-30 15:03 Revised: 2009-06-07 00:44