Abstract
Cadmium selenide (CdSe) was encapsulated in polymethylmethacrylate (PMMA) or polystyrene (PSt) by the encapsulating polymerization process. The behavior of CdSe in the encapsulating polymerization, and the photoconductivities and the photosensitive mechanism of the resulted composite materials were investigated. The polymerization was carried out by use of the initiators giving positive and negative charges to the molecular ends of the produced polymer. In both cases of the initiator, it was observed that a large part of the polymer existed in the form of stable latex polymer in the aqueous phase. The encapsulating polymer on the CdSe particles resisted to the Soxhlet extraction. The dark current, the photocurrent and the relative sensitivity of the CdSe encapsulated in PMMA were found to be enhanced as compared with CdSe and CdSe-dispersed PMMA. These values tended to increase with the increase of the encapsulating ratio. In addition, the voltage-current characteristics, temperature dependence of dark current, the light intensity dependence and the initial rising rate of photocurrent were investigated, it was concluded that the photoconductive mechanism of the CdSe encapsulated in PMMA was caused by the carrier trap.
