High efficiency submicron light-emitting resonant tunnelling diodes

We have fabricated GaAs/AlAs p‐i‐n double‐barrier resonant tunneling diodes with lateral dimensions down to 0.5 μm. There are significant differences in the electroluminescencespectra of these diodes as compared with large area diodes fabricated from the same heterostructure. In particular, a red shift of the quantum well emission line is observed together with an additional spectral line which is attributed to spatially indirect recombination. Furthermore, there is a strong increase in the low‐temperature electroluminescence efficiency for the smallest devices