PHOTOEMISSION-STUDY OF POLY(3-ALKYLTHIOPHENE)S - THE EFFECTS OF AIR AND TEMPERATURE ON THE ELECTRONIC-STRUCTURES

Ultraviolet photoemission spectroscopy (UPS) was used to study the electronic structure of poly(3-alkylthiophene)s (PATs). The effects of the heat treatment and subsequent exposure to several kinds of gasses on PATs were investigated. The temperature dependence of the electronic structure was studied with respect to consistency with the thermochromic transition. The differences which arose from the synthetic method were also observed using chemically and electrochemically prepared PATs. The values of the threshold energy and the work function were determined for each measurement. The observed UPS spectra and their changes have been discussed with regard to the shortening and lengthening of the conjugation length and to the doping and dedoping of oxygen in air.