Generation-recombination instabilities in thin-film structures

The possibility of negative differential resistance, which appears in symmetric thin-film metal-semiconductor-metal structures, is discussed. A model, which can explain to first approximation why generation-recombination processes that take place in the bulk of this sample during bipolar injection should lead to bistability, is proposed. It is shown that the design and use of these negative differential resistance structures could lead to promising new devices for detecting and processing information.