Abstract :
Research and development towards high efficiency plastic solar cells have been accelerating in recent years. Polymer-based bulk heterojunction
solar cells are offering an attractive and inexpensive concept for large scale production by solution processing as well as
advantageous flexible and aesthetic form factors. The thin film nano-morphology of bulk-heterojunction solar cells has been shown
to dramatically influence the photovoltaic performance of the devices. This article reviews the different methods used to control the film
nano-morphology of bulk-heterojunction solar cells focussing on the chemical additives during solution processing. All power conversion
efficiency limiting mechanisms of bulk-heterojunction solar cells are discussed in detail. It is shown, how the formation of optimal percolation
pathways between donor and acceptor influences the photovoltaic device performance. It is explained how the film nanomorphology
relates to light absorption, free charge carrier generation as well as charge transport to the electrodes.
2010 Elsevier Ltd. All rights reserved.
