Photocurrent spectroscopy for the investigation of charge carrier generation and transport mechanisms in organic p/n-junction solar cells

The photovoltaic behavior in a perylene/phthalocyanine hetero-p/n-junction solar cell was investigated using intensity-dependent I/V-characteristics a nd short circuit photocurrent spectroscopy. It is concluded that the charge carrier generation occurs only in a very thin active region at the contact . By optimizing the light trapping, a maximum solar AM 1.5 efficiency of ab out 2% can be obtained. A further increase requires better material propert ies or new cell structures. (C) 2000 Elsevier Science B.V. All rights reser ved.