Colloquium: Prof. Susanna M.Thon, Johns Hopkins University
Location
Physics : 401
Date & Time
October 29, 2014, 3:30 pm – 4:30 pm
Description
TITLE: Light Management in Colloidal Quantum Dot Photovoltaics
ABSTRACT: The next generation of photovoltaics seeks to push the boundaries of both efficiency and cost-effectiveness through the use of flexible platforms and new materials. Solution-processed technologies, such as semiconductor nanocrystals, offer an attractive route towards achieving these goals. Additionally, these materials are niquely suited to benefit from photonic and optical enhancements of their structures and properties. The bandgap of films composed of arrays of colloidal quantum dots (CQDs) can be tuned via the quantum confinement effect for tailored spectral utilization. The performance of CQD solar cells is currently limited by an absorption-extraction compromise, whereby photon absorption lengths in the near infrared regime exceed minority carrier diffusion lengths. Iwill review several methods aimed at overcoming this compromise. These include nanophotonic and geometric light trapping techniques, as well as jointly-tuned plasmonic-excitonic hotovoltaics. Additionally, I will discuss how nanoscale; engineering of CQDs and related materials can lead to emergent optical properties for building color-tuned optoelectronic films.
ABSTRACT: The next generation of photovoltaics seeks to push the boundaries of both efficiency and cost-effectiveness through the use of flexible platforms and new materials. Solution-processed technologies, such as semiconductor nanocrystals, offer an attractive route towards achieving these goals. Additionally, these materials are niquely suited to benefit from photonic and optical enhancements of their structures and properties. The bandgap of films composed of arrays of colloidal quantum dots (CQDs) can be tuned via the quantum confinement effect for tailored spectral utilization. The performance of CQD solar cells is currently limited by an absorption-extraction compromise, whereby photon absorption lengths in the near infrared regime exceed minority carrier diffusion lengths. Iwill review several methods aimed at overcoming this compromise. These include nanophotonic and geometric light trapping techniques, as well as jointly-tuned plasmonic-excitonic hotovoltaics. Additionally, I will discuss how nanoscale; engineering of CQDs and related materials can lead to emergent optical properties for building color-tuned optoelectronic films.