A novel spectroscopy that combines hot-electron transport methodology with external excitation stimulation is utilized to elucidate the energy spectrum of multiple-quantum-well structures. The energy distribution of carriers measured from this spectroscopy using both thermal and optical stimulation reveals the important transport mechanisms in the structure. For the multiple-quantum-well structure studied in this paper, it is noted that the energy distribution of the photoexcited electrons is extremely narrow and well separated from the lower-energy electrons; this observation is utilized to propose a new low-noise infrared transistor for liquid-nitrogen temperature operation.

• Received 7 June 1990

DOI:https://doi.org/10.1103/PhysRevB.42.9166