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.
|Original language||English (US)|
|State||Published - Mar 14 2013|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-I1-001-12
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.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.