Capacitance spectroscopy on copper indium diselenide based solar cells

The influence of gallium on the electronically active defects in copper indium diselenide based solar cells is examined. The aim is to clarify whether any detrimental deep levels are responsible for the only sublinear increase in open circuit voltage with increasing band gap for devices with molar gallium to gallium plus indium ratio (GGI) larger than 0.3. A series of samples with different GGI is investigated using deep level transient and admittance spectroscopy (DLTS and AS). For the solar cells with mixed absorber composition (0 < GGI<1) in principle the same defect spectra were found. So the bulk defects are not responsible for the 'break down' in open circuit voltage. Furthermore, for the defect signal known as N1 or ? in literature, some remarkable properties are revealed in DLTS measurements. Depending on the respective measurements conditions like the level of reverse bias voltage, height or length of the voltage pulse, either a minority carrier or a majority carrier defect signal is detected, or even a combination of both. The experimental findings cannot be explained by the overlap of two independent trap signals. Two other possible mechanisms are discussed.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Oldenburg

Year

2005

Author dc:creator

• Mertens, Verena

• [Keine Schlagwörter von Autor/in vergeben.]

Repository record source_url

http://oops.uni-oldenburg.de/88

OAI identifier oai:identifier

oai:oops.uni-oldenburg.de:88