HOT-ELECTRON LIGHT-EMITTING SEMICONDUCTOR HETEROSTRUCTURE DEVICE - TYPE-2

A novel hot electron light-emitting device is proposed which operates by the application of longitudinal electric field, i.e. in the plane o f the GaAs quantum wells, which are placed next to the junction plane of an n-Ga1-xAlxAs-p-GaAs heterostructure. Application of high electri c fields results in the transfer of hot electrons via tunnelling and t hermionic emission, from the quantum well in the depletion region, int o the GaAs inversion layer. The hot holes in the p-GaAs, initially awa y from the junction, then diffuse towards the junction plane to recomb ine with the excess hot electrons, giving rise to electroluminescence (EL) which is representative of the GaAs band-to-band emission. As the applied field is increased, a high-energy tail in the EL spectrum dev elops, and, photons with energies greater than the el-hhl transition e nergy in the quantum well are absorbed and re-emitted by the quantum w ell. Thus a second peak develops in the EL spectra which becomes stron ger with increasing applied electric field. The device has been theore tically modelled, by solving Schrodinger and Poisson's equations self- consistently, to understand the processes leading to EL emission in th e various channels. (C) 1995 Academic Press Limited