CONTACTS TO CHALCOGENIDE GLASSES.

A useful experimental feature of most amorphous semiconductors is that it is easy to make ohmic contacts. This may be explained in terms of conventional theory if there is a very high density of states in the gap. Barriers are thin enough to allow high tunnel currents to flow and therefore appear transparent to both electrons and holes. More complex configurations are described where there are interface layers or chemical reaction between metal and glass. The contrast with crystalline semiconductors is shown by I-V relations for crystalline silicon-chalcogenide glass heterojunctions and C-V measurements made with metal-oxide-glass structures. Values of surface state densities deduced from metal and semiconductor contact measurements are self-consistent.