High frequency application of hot electrons in superlattices

The properties of lateral surface superlattices (LSSLs) as high frequency devices are investigated. The two most interesting possibilities are the use of a negative differential mobility as the basis for oscillators and amplifiers similar in nature to those obtained using Gunn devices, and the possible direct interaction between high frequency electric fields and electrons undergoing Bloch oscillations. Both of these possibilties will be discussed. The possible negative resistance device applications are investigated using standard computer simulations of Gunn-like device elements. First, Monte Carlo techniques are used to estimate the hot electron drift velocity and diffusion coefficients of a prototype LSSL. These transport coefficients are then incorporated into a device simulation. By using this simulation we illustrate the possible advantages of these structures over standard GaAs Gunn devices. These advantages stem from the substantially lower diffusion coefficients, the absence of a high field saturated drift velocity and the lack of any intervalley transfer processes. The possibility that an incident high frequency electric field can interact with electrons undergoing Bloch oscillations has been previously noted. Here we extend these discussions to include scattering mechanisms by including time-varying fields in a Monte carlo simulation of hot electron transport in a LSSL.