A pulsed-radiolysis time-resolved microwave conductivity (PR-TRMC) experiment was conducted to investigate the negative effect of high-temperature annealing on the charge carrier lifetimes in microcrystalline phenyl-C 16-butyric acid methyl ester (PCBM). The air-equilibrated and evacuated PCMB sample at room temperature are identical both in end-of-pulse magnitude and in after-pulse temporal relaxation of the conductivity. The results show that irradiation does not cause any change in initial mobility or the decay kinetics of the mobile charge carriers responsible for the conductivity. In thermal-annealing procedures, the samples when heated at elevated temperature show that the decay of conductivity is faster with increasing annealing time. The decrease in lifetime of conductivity results from a thermally activated chemical rearrangement or decomposition of PCMB accompanied by the formation of trapping sites for the mobile charge carriers.
ASJC Scopus subject areas
- Materials Science(all)