Effect of Composite Layers Based on Dyes with Different Types of Conductivity on Photovoltaic Properties of CIS Films

Abstract

The effect of the deposition of layers “polymer-dye” with different types of conductivity on the surface photovoltage (V) of CuInS₂ (CIS) has been studied. The influence of composite layers depends on the molecular structure of a polymer, the type of conductivity and photosensitivity of a dye. The photovoltage growth mainly in the region of strong absorption of a dye was observed after the deposition of the composite consisted of the p-type polymethine dye and the carbazole I-contained polymer on the CIS surface. The spectral dependence of this composite in the low-absorption region is only weakly changed. On the contrary, the deposition of the composite consisted of the perylene n-type dye in polymer on CIS leads to a decrease of V, especially in the dye absorption region. A decrease of the short-wavelength slope is caused by the presence of surface recombination centers in CIS films. The above-mentioned results can be explained by the presence of a few concurrent processes, the efficiency of which strongly depends on the used polymer and the type of conductivity of a dye.

Keywords:

• CuInS₂
• organic dyes
• polymer composites
• surface photovoltage

Acknowledgments

The authors thank Prof. Dieter Meissner, Prof. A. A. Ishchenko, and Dr. J. Penndorf for the gift of DiMe-PTCDI and HITC dyes and CISCuT layers, respectively. This work is supported by INTAS Grant N 03-51-4561.