Nanocomposite titanium dioxide/polymer photovoltaic cells: effects of TiO2 microstructure, time and illumination power.

Conference item

Nanocomposite titanium dioxide/polymer photovoltaic cells have been fabricated using poly[2-(2-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene] (MEHPPV). Two different types of titanium dioxide were used, one synthesized using a sol-gel method, the other was a commercial paste. The crystal structure, porosity and absorption spectra of the titanium dioxide layers were measured, and the titanium dioxide synthesized using the sol-gel method had a much lower level of anatase. The photovoltaic properties of the ITO/TiO2/MEHPPV/Au cells, which were similar for both types of TiO2, were measured as a function of illumination power and compared with equivalent circuit models. A simple equivalent circuit model incorporating a diode, two resistances and a light induced current was inconsistent with the illumination - dependent data and was improved by adding an illumination dependent shunt resistance. A very long lived, photo-induced increase in dark current was observed, which could not be explained by a polymer degradation mechanism or an increase in temperature under illumination, but was more likely to be due to trapped charge.

Authors: Carey, M; Burlakov, V; Henry, B; Kirov, K; Webster, G

• Publication status: Published
• Journal: ORGANIC PHOTOVOLTAICS IV
• Volume: 5215
• Pages: 32-40
• Publication date: 2004-01-01
• Event title: Conference on Organic Photovoltaics IV
• DOI: 10.1117/12.508477
• ISSN: 0277-786X
• ISBN: 081945088X
• Keywords: polymer; MEHPPV; illumination power; dark current; titanium dioxide