Investigation of the s-shape caused by the hole selective layer in bulk heterojunction solar cells

Sims, Lothar; H�rmann, Ulrich; Hanfland, Robert; MacKenzie, Roderick C.I.; Kogler, F. Ren�; Steim, Roland; Br�tting, Wolfgang; Schilinsky, Pavel

Abstract

A common failure mechanism of organic solar cells is the development of an s-shaped current voltage curve. Herein, we investigated the origin of this degradation mechanism by replacing the commonly used hole selective layer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) with a co-evaporated layer of N,N?-bis(3-methylphenyl)-N,N?-bis(phenyl)benzidine (TPD) and Dipyrazino[2,3-f:2?,3?-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN). By varying the ratio of TPD to HATCN we are able to tune both the mobility and work function of the hole selective layer. Using a combination of field effect mobility measurements, Kelvin-Probe work function measurements, and numerical modeling we demonstrate that a degraded mobility of the hole selective layer leads to a buildup of charge within the device and reduction of fill factor.

Citation

Sims, L., Hörmann, U., Hanfland, R., MacKenzie, R. C., Kogler, F. R., Steim, R., …Schilinsky, P. (2014). Investigation of the s-shape caused by the hole selective layer in bulk heterojunction solar cells. Organic Electronics, 15(11), 2862-2867. https://doi.org/10.1016/j.orgel.2014.08.010

• Journal Article Type: Article
• Acceptance Date: Aug 3, 2014
• Online Publication Date: Aug 18, 2014
• Publication Date: 2014-11
• Deposit Date: Oct 30, 2018
• Publicly Available Date: Oct 30, 2018
• Journal: Organic Electronics
• Print ISSN: 1566-1199
• Electronic ISSN: 1878-5530
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: 11
• Pages: 2862-2867
• DOI: https://doi.org/10.1016/j.orgel.2014.08.010
• Keywords: Organic solar cells; s-Shape; Hole selective layer; TPD; HATCN; Quasi continuously mobility variation
• Public URL: https://nottingham-repository.worktribe.com/output/1211009
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1566119914003280
• Additional Information: This article is maintained by: Elsevier; Article Title: Investigation of the s-shape caused by the hole selective layer in bulk heterojunction solar cells; Journal Title: Organic Electronics; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.orgel.2014.08.010; Content Type: article; Copyright: Copyright © 2014 Elsevier B.V. All rights reserved.