Electrical and optical characterisation of bulk heterojunction polymer-fullerene solar cells

Manufacturing polymer-fullerene solar cells can be less expensive and less complicated as compared to inorganic solar cells. We studied transport properties of the polymer- poly3(hexyl-thiophene) (P3HT), fullerene - [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), and P3HT:PCBM blends of selected ratios. Interface potential barriers were estimated from Fowler-Nordheim and /or Richardson-Schottky emission theories. In case of ohmic contacts, the current conduction was found to be limited by the low mobilty of P3HT. Trap density was estimated from a space charge limited current model with traps distributed exponentially within the band gap. The efficiency of P3HT:PCBM solar cells improves after thermal annealing, which results in crystallisation of PCBM within the blends. The optimum P3HT:PCBM weight ratio of 1:1 corresponds to 6 monomer units of P3HT per molecule of PCBM. Extra amounts of either material introduce shielding effects which reduce exciton- splitting efficiency.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Oldenburg

Year

2005

Author dc:creator

• Chiguvare, Zivayi

• [Keine Schlagwörter von Autor/in vergeben.]

Repository record source_url

http://oops.uni-oldenburg.de/117

OAI identifier oai:identifier

oai:oops.uni-oldenburg.de:117