Geometric light trapping with a V-trap for efficient organic solar cells

Type
Article

Authors
Kim, Soo Jin
Margulis, George Y.
Rim, Seung-Bum
Brongersma, Mark L.
McGehee, Michael D.
Peumans, Peter

KAUST Grant Number
KUS-I1-001-12

Online Publication Date
2013-03-14

Print Publication Date
2013-05-06

Date
2013-03-14

Abstract
The efficiency of today’s most efficient organic solar cells is primarily limited by the ability of the active layer to absorb all the sunlight. While internal quantum efficiencies exceeding 90% are common, the external quantum efficiency rarely exceeds 70%. Light trapping techniques that increase the ability of a given active layer to absorb light are common in inorganic solar cells but have only been applied to organic solar cells with limited success. Here, we analyze the light trapping mechanism for a cell with a V-shape substrate configuration and demonstrate significantly improved photon absorption in an 5.3%-efficient PCDTBT:PC70BM bulk heterojunction polymer solar cell. The measured short circuit current density improves by 29%, in agreement with model predictions, and the power conversion efficiency increases to 7.2%, a 35% improvement over the performance in the absence of a light trap.

Citation
Kim SJ, Margulis GY, Rim S-B, Brongersma ML, McGehee MD, et al. (2013) Geometric light trapping with a V-trap for efficient organic solar cells. Optics Express 21: A305. Available: http://dx.doi.org/10.1364/OE.21.00A305.

Acknowledgements
This publication was based on work supported by the Center for Advanced Molecular Photovoltaics (CAMP) (Award No KUS-C1-015-21), made by King Abdullah University of Science and Technology (KAUST). S J. K. and G. M. acknowledges support from the King Abdullah University of Science and Technology (KAUST) Investigator Award (No. KUS-I1-001-12) and the Global Climate and Energy Project at Stanford (GCEP). S J. K. gratefully acknowledges support from the Samsung scholarship. S J. K. also thanks Jason Bloking for assistance with the measurements.

Publisher
The Optical Society

Journal
Optics Express

DOI
10.1364/OE.21.00A305

PubMed ID
24104418

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