Study of the porous silicon-poly(p phenylene-vinylene) systems

Investigations of the porous silicon/poly(p phenylene-vinylene) systems wer e carried out in order to obtain electronic devices with properties of both materials. We have studied the optical and electrical chacteristics of the devices made either by mixing the silicon grains and the polymer (composit c) or by depositing a polymer film on the silicon wafer (heterojunction). R aman, infrared and photoluminescence spectra of both types of samples showe d that there was no noticeable reaction between the constituents. However, the photuluminescence activity was dominated by the polymer. The current-vo ltage characteristics obtained on devices using the composites as an active layer showed that the threshold voltage was improved as compared with diod es using only polymer. In heterojunction devices, the threshold voltage was higher than that of silicon diodes and the conduction mechanisms are simil ar to those occuring in porous silicon sample.