Terahertz oscillations in an In0.53Ga0.47As submicron planar Gunn diode

Abstract

The length of the transit region of a Gunn diode determines the natural frequency at which it operates in fundamental modethe shorter the device, the higher the frequency of operation. The long-held view on Gunn diode design is that for a functioning device the minimum length of the transit region is about 1.5μm, limiting the devices to fundamental mode operation at frequencies of roughly 60 GHz. Study of these devices by more advanced Monte Carlo techniques that simulate the ballistic transport and electron-phonon interactions that govern device behaviour, offers a new lower bound of 0.5μm, which is already being approached by the experimental evidence that has shown planar and vertical devices exhibiting Gunn operation at 600nm and 700nm, respectively. The paper presents results of the first ever THz submicron planar Gunn diode fabricated in In0.53Ga0.47As on an InP substrate, operating at a fundamental frequency above 300 GHz. Experimentally measured rf power of 28 µW was obtained from a 600 nm long ×120 µm wide device. At this new length, operation in fundamental mode at much higher frequencies becomes possible -the Monte Carlo model used predicts power output at frequencies over 300 GHz.

High-Voltage Breakdown and the Gunn Effect in GaAs/AlGaAs Nanoconstrictions

“…This issue is potentially one of considerable significance, however, with implications for the development of terahertz (THz) sources [10]- [16]. Although the present work does not address these proposals directly, it nonetheless represents an important step forward by demonstrating the manifestations of the Gunn effect in the current-voltage characteristics of semiconductor nanoconstrictions (NCs).…”

Research on the origin of negative effect in uniform doping GaN-based Gunn diode under THz frequency

“…Recently, many efforts have been made to improve the efficiency, operating frequency, and output power of Gunn diodes, both in vertical and in planar [3][4][5]. What is more, the electron energy relaxation time in GaN is much smaller than that in traditional III-V materials such as GaAs [6,7].…”

Sub-Terahertz Emission from Field-Effect Transistors

“…A saturation velocity is calculated to be equal to about 10 5 m/s which gives the estimation of the frequency of oscillations of 100 GHz which is an order of magnitude higher than observed. However, one has to take into account an extremely approximative character of this estimation and the fact that both numerical [11,12] and experimental observations [13] indicate a strong dependence of the Gunn frequency on material parameters of a particular GaInAs heterostructure considered.…”