Quantum confinement effects in highly conducting, ultrathin polyaniline films pursued through spectroscopic investigations

Polyaniline (PANI) is well-known for its remarkable electrical and optical properties which find immense applications in polymer optoelectronics. Though extensive work has been reported in polyaniline samples both in bulk and thin film forms, much attention has not been paid to investigate the quantum confinement effects in ultrathin polyaniline films. The present work is devoted to the search for quantum confinement effects in ultrathin polyaniline films having nanometer thickness, prepared from m-cresol, through conventional and less sophisticated spectroscopic techniques. Remarkable blue-shift has been observed in the absorption spectrum of these samples. Much intense photo-luminescent emission with considerable blue-shift observed in these ultrathin films is cited as the clear evidence for confinement effects.