A TUNABLE HOT-ELECTRON LIGHT EMITTER

We demonstrate the operation of a novel tunable wavelength surface emi tting device. The device is based on a p-GaAs and n-Ga1-xAlxAs heteroj unction containing an inversion layer on the p-side, and GaAs quantum wells on the n-side, and is referred to as HELLISH-II (hot-electron li ght emitting and lasing in semiconductor heterojunction). The device u tilizes hot-electron longitudinal transport and, therefore, light emis sion is independent of the polarity of the applied voltage. Because of this symmetric property, the device can perform light logic functions . The wavelength of the emitted tight can be tuned with the applied bi as from GaAs band-to-band transition in the inversion layer to e1-hh1 transition in the quantum wells. The operation of the device requires only two diffused in point contacts. Therefore, a two-dimensional arra y of surface emitters can be fabricated very cheaply and easily. Theor etical modelling of the device operation is carried out and compared w ith the experimental results. An optimized structure for high-efficien cy device operation, as based on our model calculations, is also propo sed.