Effects of Doping States of Polyaniline Thin Films on Their Photo-Responsive Properties under Visible and Near-Infrared Irradiation

Abstract

The photo-responsive characteristics of polyaniline (PANI) thin films are investigated as a function of the doping states. The doping levels are controlled by treating as-prepared, acid-doped PANI with aqueous ammonia solutions. Spectroscopic analyses confirm the changes in the doping states by evolution or decrease of characteristic peaks. The electrical and photo-responsive properties are significantly affected by the doping states of the PANI thin films. The photocurrent and photovoltage under irradiation of controlled wavelengths from various laser sources are measured. While the photocurrent follows the trends of electrical conductivity upon dedoping, the photovoltage is related to the absorption and photocharge generation of the PANI samples.