APS March Meeting 2012
Volume 57, Number 1
Monday–Friday, February 27–March 2 2012;
Boston, Massachusetts
Session D27: Invited Session: Materials for Energy Applications
2:30 PM–5:30 PM,
Monday, February 27, 2012
Room: 258AB
Sponsoring
Units:
DMP GERA
Chair: Robert Nemanich, Arizona State University
Abstract ID: BAPS.2012.MAR.D27.4
Abstract: D27.00004 : Quantum-well and quantum-dot structures for high-efficiency photovoltaics
4:18 PM–4:54 PM
Preview Abstract
Abstract
Author:
Edward Yu
(The University of Texas at Austin)
Quantum-well and quantum-dot semiconductor heterostructures offer a variety
of opportunities for achieving photovoltaic power conversion efficiencies in
excess of the Shockley-Queisser limit for single-homojunction solar cells.
However, realization of such efficiencies is likely to require a combination
of very high quality epitaxial growth or nanostructure synthesis to minimize
carrier trapping and recombination, detailed understanding and analysis of
optical absorption and nonequilibrium carrier transport processes, and light
trapping to enable efficient optical absorption in very thin device layers.
We discuss work in which GaAs/InGaAs/InAs semiconductor quantum-well and
quantum-dot solar cells are realized in designs that enable efficient
collection of photogenerated carriers from quantum-wells and dots, and
combined with subwavelength-scale metal and dielectric structures that
enable incident photons to be scattered into guided optical modes within a
thin-film device, thereby enabling increased absorption efficiency in very
thin device layers. Several aspects of this work will be addressed.
Measurement of electric-field-dependent photocurrent response enables design
of structures in which photogenerated carriers are collected efficiently
from quantum-well or quantum-dot structures in the intrinsic region of a
p-i-n junction solar cell. Processing to remove epitaxially grown device
layers from their original growth substrate enables metal and dielectric
nanostructures to be designed and integrated with the semiconductor
epitaxial layer structures to scatter incident photons into strongly guided
optical modes within the semiconductor. Finally, detailed analysis of
quantum-well and quantum-dot optical absorption as well as optical mode
structure within the device enables optimization of the absorption and mode
profiles to achieve maximum power conversion efficiency. Both computational
and experimental results derived from these approaches will be described.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.MAR.D27.4