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Molecular Multilayer Organic Solar Cells with Large Excitonic Diffusion Length

Published online by Cambridge University Press:  26 February 2011

Seunghyup Yoo ,
William J Potscavage ,
Benoit Domercq ,
Sung-Ho Han ,
Dean Levi  and
Bernard Kippelen
Seunghyup Yoo
Affiliation:
syoo@ee.gatech.edu, Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA, 30332-0250, United States
William J Potscavage
Affiliation:
william.potscavage@ece.gatech.edu, Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA, 30332-0250, United States
Benoit Domercq
Affiliation:
benoit.domercq@ece.gatech.edu, Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA, 30332-0250, United States
Sung-Ho Han
Affiliation:
sung-ho_han@msn.com, NREL, Golden, CO, 80401, United States
Dean Levi
Affiliation:
dean_levi@nrel.gov, NREL, Golden, CO, 80401, United States
Bernard Kippelen
Affiliation:
bernard.kippelen@ece.gatech.edu, Georgia Institute of Technology, School of Electrical and Computer Engineering, 777 Atlantic Dr., Atlanta, GA, 30332-0250, United States
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Abstract

We report on the photovoltaic properties of organic solar cells based on pentacene and C60 thin films. A peak external quantum efficiency (EQE) of 69 % at a wavelength of λ = 668 nm is achieved upon optimization of the exciton blocking layer (EBL) thickness. Complex optical functions of pentacene films are measured as a function of wavelength by spectroscopic ellipsometry and used to analyze the EQE spectra. Detailed analysis of the EQE spectra indicate that the pentacene layers exhibit large excitonic diffusion lengths of ∼70 nm and that the performance improvement in EQE can be attributed to the influence of the thickness of the EBL layer on the carrier collection efficiency.

Keywords

photovoltaicorganicsemiconducting
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 965: Symposium S – Organic Electronics – Materials, Devices and Applications , 2006 , 0965-S11-01
Copyright
Copyright © Materials Research Society 2007

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References

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