Evidence of photoluminescence quenching in poly(3-hexylthiophene-2,5-diyl) due to injected charge carriers

Photoluminescence spectra of poly(3-hexylthiophene-2,5-diyl) (P3HT) has been studied in forward and reverse bias direction in an indium tin oxide (ITO)/P3HT/Al Schottky device. It has been observed that photoluminescence quenching is relatively higher in forward direction and the quenching pattern gets reversed when a thin insulating layer of poly(4-vinylphenol) is coated on ITO. The observed behavior of photoluminescence quenching pattern has been explained on the basis of interaction of the injected charge carriers with the excitons generated in the bulk of P3HT together with the interaction of excitons with the applied electric field.