Planar Gunn-effect devices

Traditional Gunn diode structures are constructed vertically, limiting the ease with which they may be integrated into cavities and composite systems. Recently there has been a resurgence of interest in planar Gunn structures, which do not share this problem and have other potential advantages such as with respect to frequency and power output. Our work targets structures with designs moderately similar to those of HEMT devices and composed primarily of inexpensive GaAs and AlGaAs materials. Monte Carlo transport modelling has been instrumental in predicting the operation of these devices and consequently their design. Physically realised devices have been measured to produce fundamental-mode signals at well over 0.1 THz, with power level in the µW range at the present time. Recent developments in these devices are presented, including the increased scope that their planar design provides for modulating current output through novel contact design.