Hot electron effects on the operation of potential well barrier diodes

Abstract

A study has just been carried out on hot electron effects in GaAs/Al0.3Ga0.7As potential well barrier (PWB) diodes using both Monte Carlo (MC) and drift-diffusion (DD) models of charge transport. We show the operation and behaviour of the diode in terms of electric field, mean electron velocity and potential, mean energy of electrons and Γ-valley population. The MC model predicts lower currents flowing through the diode due to back scattering at anode (collector) and carrier heating at higher bias. At a bias of 1.0 V, the current density obtained from experimental result, MC and DD simulation models are 1.35, 1.12 and 1.77 μA/μm2 respectively. The reduction in current over conventional model, is compensated to a certain extent because less charge settles in the potential well and so the barrier is slightly reduced. The DD model results in higher currents under the same bias and conditions. However, at very low bias specifically, up to 0.3 V without any carrier heating effects, the DD and MC models look pretty similar as experimental results. The significant differences observed in the I–V characteristics of the DD and MC models at higher biases confirm the importance of energy transport when considering these devices.

Improvement on Well Design and Operation of Potential Well Barrier Diodes

“…and 150 respectively with a GaAs well thickness of 30 . The MC model has been discussed in previous report on the PWB diode [3], [6] and for the study of Gunn diodes [10] and has been successfully proven to be an effective tool for studying such similar structures especially at high electric fields where consideration to carrier heating is of utmost importance. The scattering mechanism used in the simulation are the inter-valley, acoustic and polar phonon scattering and the effect of non-parabolicity was considered.…”

“…Just like Planar Doped Barrier diodes (PDB) [1], [2] and other heterostructure barrier devices, Potential Well Barrier diodes (PWB) studied in [3][4][5][6] have shown prospects of applications in detector and mixers. The diode has a lot of advantages compared to similar devices for the same purpose.…”