DISCRETE ELECTROLUMINESCENCE LINES IN SUBMICRON P-I-N RESONANT-TUNNELING DIODES

We have fabricated GaAs/AlAs p-i-n double barrier resonant tunnelling diodes with active lateral dimensions down to 0.25 mu m(2) using optic al lithography and wet etching. Many devices have been investigated an d systematic variations in the quantum well emission have been observe d as the device size is decreased. We observe a red shift of the quant um well recombination lines. In addition a new line is observed at low er energy in the spectra of the smallest devices. The quantum well lum inescence efficiency is found to be constant down to the smallest devi ce size.