Open AccessDetailed optical modelling and light-management of thin-film organic solar cells with consideration of small-area effects
Author(s) -
Benjamin Lipovšek,
Andrej Čampa,
Fei Guo,
Christoph J. Brabec,
Karen Forberich,
Janez Krč,
Marko Topič
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.00a176
Subject(s) - materials science , foil method , optics , organic solar cell , substrate (aquarium) , thin film , reflection (computer programming) , solar cell , optoelectronics , energy conversion efficiency , composite material , nanotechnology , computer science , geology , oceanography , physics , programming language , polymer
We present detailed numerical and experimental investigation of thin-film organic solar cells with a micro-textured light management foil applied on top of the front glass substrate. We first demonstrate that measurements of small-area laboratory solar cells are susceptible to a significant amount of optical losses that could lead to false interpretation of the measurement results. Using the combined optical model CROWM calibrated with realistic optical properties of organic films and other layers, we identify the origins of these losses and quantify the extent of their influence. Further on, we identify the most important light management mechanisms of the micro-textured foil, among which the prevention of light escaping at the front side of the cell is revealed as the dominant one. Detailed three-dimensional simulations show that the light-management foil applied on top of a large-area organic solar cell can reduce the total reflection losses by nearly 60% and improve the short-circuit current density by almost 20%. Finally, by assuming realistic open-circuit voltage and especially the realistic fill factor that deteriorates as the absorber layer thickness is increased, we determine the optimal absorber layer thickness that would result in the highest power conversion efficiency of the investigated organic solar cells.