抄録
Thermal and electrical properties in hybrid materials consisting of p-type amorphous selenium and n-type In2Se3 nanocrystals have been investigated. The In-Se system shows a monotectic reaction at the selenium rich region in the solidification process. A rapid quenching method was therefore used in order to fabricate amorphous samples embedding nanocrystals of which the average size was 45 nm under the present condition.
In the hybrid samples, melting point depression is observed by DTA measurements, and increases with increasing the numbers of the nanocrystals for an effect of the interface between the nanocrystals and the amorphous Se matrix. Green bodies of the amorphous Se are found to show negative differential conductivity (NDC). It seems that NDC is caused from dangling bonds, whose numbers are determined in the amorphization process. The dependence of the electrical conductivity of the hybrid green bodies on the In2Se3 concentration changes rapidly due to percolation transition. Electrical modification of amorphous Se can be performed by the addition of n-type nanocrystals, In2Se3. It is important for material design to modify the electrical properties without any restriction, because the electrical modification of an amorphous matrix by adding impurities has a solubility limit. The electrical properties in the present hybridisation are described in terms of the interfacial effect and the percolation phenomenon.
