PHOTOCURRENT EXCITATION-SPECTRA OBSERVED WITH AU AL HETEROELECTRODES BIASED REVERSELY AND REFLECTION SPECTRA IN TRANS-POLYACETYLENE

To understand the low lying excited states of trans-polyacetylene, optical properties were studied at room temperature on carefully prepared samples by measuring photocurrent (PC) and photovoltage excitation spectra as well as optical absorption and reflectance. The 1.4 eV PC peak, the appearance of which sensitively depends on the sample quality, is correlated with some additional absorption sticking to the intrinsic absorption edge. An enhancement of PC with Au-A1 electrodes biased reversely was observed in excitation spectra between 1.5 approximately 2.0 eV, indicating that the formation of excitons causes three reflection peaks in this spectral region.