Organic Solar Cell

The project "Organic Solar Cell" forms part of a cooperation on renewable energies financed by the federal ministry for education and research (BMBF). Object is the development of efficient solar cells based on organic compounds. It is hoped to make accessible a new, cheap technology to utilise regenerative energy sources.

The principle of an organic solar cell consists in one component's releasing of electrons (donor) under the influence of light and in another component's receiving them (acceptor).
After the seperation of the thus generated electron-hole-pairs at the donor-acceptor-interface the charge carriers are discharged to the electrodes on either side as a photo current. The components can either form layers (hetero structure) or a homogeneous mixture. Typically a thickness of roughly 50 nm per layer has proved successful.

Fig. 1. Structure of an organic solar cell.

Zn-Phthalocyanine serves as a donor, C₆₀ as
acceptor. The transparent ITO (Indium-Tin-Oxide)
and aluminium are used as electrodes. PEDOT:PSS
and Bathocuproine form buffer layers, that adjust
the physical and electrical properties of the active
layer to the ones of the electrodes.

It has been shown that the purity of the compounds has great influence on the electrical properties of the solar cell. To avoid impurities in the layers, we work almost exclusively with materials, that can be deposited by thermal evaporation in high vacuum. Zn-Phthalocyanine and C₆₀ is a pair of donor and acceptor, whose suitability has previously been demonstrated in publications.

Staff of working group
Bochukov, Dipl.-Chem. Ivelin	8062 - 42405	ivelin.bochukov@helmholtz-berlin.de
Fostiropoulos, Dr. Konstantinos	8062 - 42719	fostiropoulos@helmholtz-berlin.de
Mete, Tayfun	8062 - 42159	tayfun.mete@helmholtz-berlin.de
Schindler, Wolfram	8062 - 42159	wolfram.schindler@helmholtz-berlin.de
Wiesner, Sven	8062 - 42988	sven.wiesner@helmholtz-berlin.de