Efficiency enhancement of polymer fullerene solar cells

PhD ceremony: M. Lenes, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Thesis: Efficiency enhancement of polymer fullerene solar cells

Promotor(s): prof. P.W.M. Blom

Faculty: Mathematics and Natural Sciences

 

Polymer solar cells are considered to be a promising candidate for a flexible, light weight, large area, and most importantly low cost energy source. Despite many progress is made in understanding and improving of this type of solar cell, the efficiencies achieved are still too low for large scale commercialization. Martijn Lenes describes in his thesis how he analyzed several critical loss mechanism in solar cells, based on a polymer as an electron donor and a fullerene as an electron acceptor and he gives strategies to improve the efficiency. Several of these strategies are used in the development of new materials and have been tested. The fabricated cell are tested by him and analyzed with the current models which exist for these type of devices. In some cases he adapted the existing models to account for newly observed phenomenon. He shows that in the optimization of the energy levels of the used materials a large improvement in efficiency can be obtained. In some cases this resulted in the ability of the solar cell to absorb a larger part of the solar spectrum, in another case this resulted in an enhanced output voltage of the solar cell. In the latter case, using a new fullerene resulted in a relative improvement of the efficiency of 20% compared to the model polymer:fullerene system, a breakthrough in performance.