A Caltech Library Service

Solar Cell Light Trapping beyond the Ray Optic Limit

Callahan, Dennis M. and Munday, Jeremy N. and Atwater, Harry A. (2012) Solar Cell Light Trapping beyond the Ray Optic Limit. Nano Letters, 12 (1). pp. 214-218. ISSN 1530-6984. doi:10.1021/nl203351k.

PDF - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


In 1982, Yablonovitch proposed a thermodynamic limit on light trapping within homogeneous semiconductor slabs, which implied a minimum thickness needed to fully absorb the solar spectrum. However, this limit is valid for geometrical optics but not for a new generation of subwavelength solar absorbers such as ultrathin or inhomogeneously structured cells, wire-based cells, photonic crystal-based cells, and plasmonic cells. Here we show that the key to exceeding the conventional ray optic or so-called ergodic light trapping limit is in designing an elevated local density of optical states (LDOS) for the absorber. Moreover, for any semiconductor we show that it is always possible to exceed the ray optic light trapping limit and use these principles to design a number of new solar absorbers with the key feature of having an elevated LDOS within the absorbing region of the device, opening new avenues for solar cell design and cost reduction.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Atwater, Harry A.0000-0001-9435-0201
Additional Information:© 2011 American Chemical Society. Received: September 26, 2011. Revised: December 2, 2011. Publication Date (Web): December 12, 2011. The authors acknowledge helpful discussions with S. Burgos, E. Feigenbaum, E. Kosten, J. Fakonas, D. O’Carroll, J. Grandidier, V. E. Ferry, and K. Aydin. This work was supported by the Energy Frontier Research Center program of the Office of Science of the Department of Energy under Grant DESC0001293 (J.N.M. and H.A.A.) and by Department of Energy under Grant DOE DE-FG02-07ER46405 (D.M.C.).
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0001293
Department of Energy (DOE)DE-FG02-07ER46405
Subject Keywords:Photovoltaic cell, solar cell, local density of optical states (LDOS), light trapping, plasmonic, nanophotonic
Issue or Number:1
Record Number:CaltechAUTHORS:20120203-153912353
Persistent URL:
Official Citation: Solar Cell Light Trapping beyond the Ray Optic Limit Dennis M. Callahan, Jeremy N. Munday, and Harry A. Atwater Nano Letters 2012 12 (1), 214-218
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29136
Deposited By: Ruth Sustaita
Deposited On:06 Feb 2012 18:14
Last Modified:09 Nov 2021 17:04

Repository Staff Only: item control page