High Radiative Efficiency (Al)GaAs Nanowires for Optoelectronic Devices

Speaker: Sudha Mokkapati
Affiliation: Australian National University

GaAs is the most studied and used compound semiconductor material for optoelectronic device applications. Its applications, however, have been very limited in the nanowire configuration because of its large surface recombination velocity (~106 cm/s). Large surface recombination velocity coupled with large free surface area in nanowires results in surface state assisted non-radiative recombination and degrades the optoelectronic quality of the GaAs nanowires.

I will discuss and present experimental results on four different approaches to enhance the optoelectronic quality of GaAs nanowires: (i) surface passivation, (ii) coupling to plasmonic cavities, (iii) coupling to hybrid photonic-plasmonic cavities, and (iv) p-doping. I will discuss the implications of these approaches on the radiative efficiency of GaAs nanowires and demonstrate lasing from GaAs nanowires, as a direct evidence of improved optoelectronic quality.

ARC (Australian Research Council) is acknowledged for financial support, NCI (National Computational Infrastructure) for computational resources and ANFF (Australian National Fabrication Facility) for facility access.

Dr. Mokkapati obtained her Ph.D. in 2008 from the Department of Electronic Materials Engineering (EME), the Australian National University (ANU). During her Ph.D. candidature she had demonstrated III-V semiconductor quantum-dot based integrated optoelectronic devices. She was a post-doctoral Fellow at the centre for sustainable energy systems (CSES), ANU from 2008-2011 working on light management for solar cells. She moved back to EME in 2011 as a Super Science Fellow. Currently, she is a Research Fellow and her research focuses on the light matter interactions in III-V semiconductor nanostructures for optoelectronic devices.

For more information, contact Prof. Diana Huffaker ( )

Date(s) - Jul 14, 2016
11:00 am - 12:00 pm

E-IV Maxwell Room #57-124
420 Westwood Plaza - 5th Flr. , Los Angeles CA 90095