Title : Growth of dilute III V N and III V Bi semiconductors by liquid phase epitaxy
Dilute III-V- Nitride and III-V- Bismide materials have found great interest as promising materials for the fabrication f sources and detectectrs in the near infrared region. These materials are obtained by adding very little amounts of N or Bi to the base III-V crystal and this causes a large increase in the energy band gap of the material. This provides an easy way for the tuning of the band gap of the material by controlling the N or Bi to the semiconductor. These materials are grown by MBE and MOCVD techniques. We have grown them using a far simpler and hazard free liquid phase epitaxy (LPE) technique. GaAsN grown by this technique indicated a maximum N content in the solid as 0.5 wt% which upon addition of Li3N to the growth melt increased to 0.9%. The technique also successfully yielded GaSbN, InPN and InAsN epitaxial layers. By adding controlled amounts of Bi to a GaSb growth melt we have been able to produce GaSbN layers. Various interesting properties of this material have been obtained. We have also grown InPBi, InSbBi and InPNBi epitaxial layers by LPE technique. The properties f these materials will be discussed in details.
Dr. Sunanda Dhar has retired as a professor with the Department of Electronic Science, University of Calcutta in 2017 and is still associated with the same Department as an active researcher. For the past three decades, he has been working on the experimental and the theoretical properties of group III-V compound semiconductors grown by liquid phase epitaxy (LPE). He was the first to develop LPE techniques for the growth of dilute nitride and bismide semiconductors. He has spent 2 years at the University of Michigan, USA during 1984-86 working on the deep level studies of various III-V semiconductor structures grown by LPE, MBE and MOCVD techniques. He also worked as a visiting scientist for 9 months at Lancaster University, UK during 2008-09 working on the implementation of his LPE technique for the growth of dilute nitride semiconductors for mid-infrared detectors. He has made 90 publications in refereed journals, 85 papers in conference proceedings, 56 invited talks, edited one conference proceedings and two patents. Dr. Dhar has written a book chapter entitled `Deep levels in III-V compound semiconductors grown by molecular beam epitaxy` in the series `Semiconductors and Semimetals` (1986) of Academic Press, USA and another book chapter entitled `Group III-V bismide materials grown by liquid phase epitaxy` in the book `Bismuth-Containing Compounds` of Springer Series in Materials Science in 2013. He is the life member of the Semiconductor Society of India and a member of the Materials Research Society of Singapore.