Electrical and optical properties of the four-terminal double-heterostructure opto-electronic switch

The authors extend the theory of the three-terminal double-heterostructure opto-electronic switch (DOES) device, in which the third terminal (the injector) makes contact to the bulk section of the active region, to the four-terminal DOES, in which the fourth terminal (the source) accesses the inversion channel at the n-n heterojunction. The source is shown to be capable of initiating switching at lower current densities than the injector. The effects of incident light on the device are also examined, yielding results similar to the injection of carriers at the source and injector. Incomplete ionization of the charge sheet and two-dimensional quantum effects in the channel, which have been neglected in previous DOES models, have been included. These effects are shown to affect significantly the characteristics of the device and to reduce the discrepancy between simulated and experimental results