TY  - JOUR
AU  - Kaienburg, Pascal
AU  - Hartnagel, Paula
AU  - Pieters, Bart
AU  - Yu, Jiaoxian
AU  - Grabowski, David
AU  - Liu, Zhifa
AU  - Haddad, Jinane
AU  - Rau, Uwe
AU  - Kirchartz, Thomas
TI  - How Contact Layers Control Shunting Losses from Pinholes in Thin-Film Solar Cells
JO  - The journal of physical chemistry  / C C, Nanomaterials and interfaces
VL  - 122
IS  - 48
SN  - 1932-7455
CY  - Washington, DC
PB  - Soc.66306
M1  - FZJ-2019-00332
SP  - 27263 - 27272
PY  - 2018
AB  - An absorber layer that does not fully cover the substrate is a common issue for thin-film solar cells such as perovskites. However, models that describe the impact of pinholes on solar cell performance are scarce. Here, we demonstrate that certain combinations of contact layers suppress the negative impact of pinholes better than others. The absence of the absorber at a pinhole gives way to a direct electrical contact between the two semiconducting electron and hole transport layers. The key to understand how pinholes impact the solar cell performance is the resulting nonlinear diodelike behavior of the current across the interface between these two layers (commonly referred to as a shunt current). Based on experimentally obtained data that mimic the current–voltage characteristics across these interfaces, we develop a simple model to predict pinhole-induced solar cell performance deterioration. We investigate typical contact layer combinations such as TiO2/spiro-OMeTAD, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)/phenyl-C61-butyric acid methyl ester, and TiO2/poly(3-hexylthiophene). Our results directly apply to perovskite and other emerging inorganic thin-film solar cells, and the methodology is transferable to CIGS and CdTe. We find substantial differences between five commonly applied contact layer combinations and conclude that it is not sufficient to optimize the contact layers of any real-world thin-film solar cell only with regard to the applied absorber. Instead, in the context of laboratory and industrial fabrication, the tolerance against pinholes (i.e., the mitigation of shunt losses via existing pinholes) needs to be considered as an additional, important objective.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000452693300017
DO  - DOI:10.1021/acs.jpcc.8b09400
UR  - https://juser.fz-juelich.de/record/859476
ER  -