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OSE Dissertation Defense with Sharmin Haq, Ph.D. Candidate

Departmental News

Sharmin Haq

Posted: November 27, 2018

Date: Thursday, November 29, 2018 

Time:  10:30 AM

Location:  CHTM, Room 101

Map to CHTM:

http://chtm.unm.edu/about/map-directions.html

Parking passes are available at the receptionist desk.  The CHTM building is equipped with ADA accommodations as well as parking spaces.

Abstract:

Plasmonic modes in metal nanostructures enable light confinement at subwavelength scales. This field confinement is important for exploring the possibilities of nanotechnology in miniaturization of optics as well as for the advancement of optoelectronic devices, such as photodetectors, photovoltaics, and light-emitting diodes. This expanding plasmonic applications, makes it necessary to have fundamental understanding about the plasmon coupled system which has not yet been completely understood. In this dissertation, the optical interactions between resonant plasmonic nanoparticles and polarizable substrates (semiconductor and metal) have been investigated by analyzing the scattering properties of the plasmonic nanoparticles and the photoluminescence (PL) of emitters embedded inside semiconductor substrate. Plasmon enhanced carrier generation and photon emission are investigated by monitoring the PL intensity enhancement at room temperature, by coupling colloidal gold nanorods (AuNRs) to InAs QDs, embedded in InGaAs/GaAs quantum well. The length scales of the near-field confinement, carrier diffusion, and excitation energy transfer to the metal surface, have been determined systematically both experimentally and theoretically by controlling the GaAs capping layer thickness with sub-nanometer accuracy. After establishing the distance dependency, the temperature dependence of the plasmon enhanced carrier generation and photon emission are studied by analyzing QDs PL for representative samples. We demonstrate the possibility of obtaining precise control at atomic length scale and uniform conformal deposition of Al2O3 dielectric spacer layer using atomic layer deposition. Super-resolved optical interaction has been demonstrated for the metallic gold particle-film system separated by Al2O3 spacer layer.