Impact of Ion Implantation on Quantum Dot Heterostructures and Devices

This book looks at the effects of ion implantation as an effective post-growth technique to improve the material properties, and ultimately, the device performance of In(Ga)As/GaAs quantum dot (QD) heterostructures. Over the past two decades, In(Ga)As/GaAs-based QD heterostructures have marked their superiority, particularly for application in lasers and photodetectors. Several in-situ and ex-situ techniques that improve material quality and device performance have already been reported. These techniques are necessary to maintain dot density and dot size uniformity in QD heterostructures and also to improve the material quality of heterostructures by removing defects from the system. While rapid thermal annealing, pulsed laser annealing and the hydrogen passivation technique have been popular as post-growth methods, ion implantation had not been explored largely as a post-growth method for improving the material properties of In(Ga)As/GaAs QD heterostructures. This work attempts to remedy this gap in the literature. The work also looks at introduction of a capping layer of quaternary alloy InAlGaAs over these In(Ga)As/GaAs QDs to achieve better QD characteristics. The contents of this volume will prove useful to researchers and professionals involved in the study of QDs and QD-based devices.

Dr. Arjun Mandal is currently working as a Research Associate at the University of Wisconsin-Madison, USA. His current work involves GaAs based Hydride Vapor Phase Epitaxy (HVPE) synthesis of lattice-mismatched "virtual substrates", and materials synthesis for advanced Quantum Cascade Laser (QCL) development. He also works on modeling of vapor phase epitaxy growths using computational fluid dynamics. Previously, he worked at the Semiconductor Materials and Processes Laboratory (SMPL) at Chonbuk National University, South Korea. During this period, his research works included growth and characterizations of InGaN/GaN quantum dots and multi quantum well (MQW) heterostructures on GaN nanowires for LED device applications. For this purpose, growths were done with nitride based MOCVD system. Also, He had worked on GaN nanowire-graphene based hybrid structures for ultraviolet photoconductive device applications. Prior to joining SMPL, he had spent six months in the Electrical Engineering Department, IIT Bombay as a Research Associate from where he completed his Ph.D. in 2014 in Microelectronics; he received his M. Tech. from Institute of Radiophysics and Electronics, University of Calcutta in 2008. The topic of his doctoral research was effect of ion implantation on the In(Ga)As/GaAs based quantum dot (QD) heterostructures, mainly Infrared Photodetectors. He has expertise in Molecular Beam Epitaxy (MBE) system, responsible for growth optimization and growth of various In(Ga)As/GaAs QD heterostructures over three years during his Ph. D. at IIT Bombay; also had worked on material and optical characterizations of dots, fabrications and different characterizations of the optoelectronics devices. He had served as a Vice-chair of IEEE Student Branch, Calcutta section during the period of 2007-08.

Subhananda Chakrabarti received his M.Sc. and Ph.D. degrees from the Department of Electronic Science, University of Calcutta, Kolkata, India in 1993 and 2000, respectively. He was a Lecturer in the Dept. of Physics, St. Xavier's College, Kolkata. He has been a Senior Research Fellow with the University of Michigan, Ann Arbor, from 2001 to 2005, a Senior Researcher with Dublin City University, Dublin City, Ireland, from 2005 to 2006, and a Senior Researcher (RA2) with the University of Glasgow, Glasgow, U.K., from 2006 to 2007. He joined as an Assistant Professor in the Department of Electrical Engineering, IIT Bombay, Mumbai, India, in 2007. Presently, he is a Professor in the same department. He is a Fellow of the Institution of Electrical and Telecommunication Engineers (IETE) India and also a Member of the IEEE, MRS USA, SPIE USA etc. He is the 2016 medal recipient of the Materials Research Society of India and was also awarded the 2016 NASI-Reliance Industries Platinum Jubilee Award for Application Oriented Innovations in Physical Sciences. He serves as an Editor of the IEEE Journal of Electron Device Society. He has authored more than250 papers in international journals and conferences. He has also co-authored a couple of book chapters on intersubband quantum dot detectors. Dr. S. Chakrabarti serves as reviewer for a number of international journals of repute such as Applied Physics Letters, Nature Scientific Reports, IEEE Photonics Technology Letters, IEEE Journal of Quantum Electronics, Journal of Alloys and Compound, Material Research Bulletin etc. His research interests lie in compound (III-V and II-VI) semiconductor based optoelectronic materials and devices.