Subhananda Chakrabarti

INFRARED PHOTONIC DEVICES GROUP

Department of Electrical Engineering, IIT Bombay

Research highlights

 

The highlights reported here are from samples/devices which have been grown, fabricated and characterized in-house at IIT Bombay: hence the effort is completely indigenous.

 

• Demonstrated first successful fabrication of MWIR Type II Superlattice GaSb-based 320×256 Focal Plane Array in the country

 

• Developed prototypes of the 320×256 Quantum Dot Infrared Photodetector(QDIP)-based Focal Plane Array THERMAL IMAGERS for the first time in the country, which represent India’s most cutting-edge thermal imaging technology

 

• Demonstrated state-of-the-art characteristics in indigenously developed quaternary-capped QDIPs, which surpassed all previous world records in terms of a combination of very high responsivity with detectivity

 

• Developed multicolour, broadband, quaternary-capped InAs/GaAs QDIPs with ultra-narrow line-widths.

 

• Developed ex-situ ion implantation in QDIPs, which drastically enhanced their signal-to-noise ratio i.e. detectivity

 

• Has developed a theoretical model to explain the effect of thermal annealing on the photoluminescence of InAs/GaAs quantum dots (QDs); this model has the potential to assist in more precisely engineering the optical properties of QD materials for specific device applications.

 

• Has also made noteworthy contributions towards the development of nanoscale strain-coupled quantum dot heterostructures for possible application to telecommunication lasers. In particular, he demonstrated for the first time that strain coupling inhibits interdiffusion of materials and thereby induces higher thermal stability in nanostructures; a result that has the potential to spur development of higher efficiency telecommunication (1.3-1.55 µm) lasers

 

• Has also recently demonstrated very stable p-type doping by PIII (plasma immersion ion implantation) for the first time in ZnO, a material which is thought to be more promising that GaN for solid state lighting applications

 

• Demonstrated a homojunction ZnO-based UV (ultra-violet) light emitting diode (LED), using stable p-type doping via PIII (plasma immersion ion implantation)

 

• Have also extensively promoted undergraduate research at IIT Bombay and more than 20 (twenty) international journal papers have been published where the undergraduate is either the first or a coauthor.

 

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