Demonstration of Lateral p-n Subband Junctions in Si Delta-Doped Quantum Wells on (111)A Patterned Substrates

The lateral subband p-n junction (LSJ) is demonstrated through a Si delta-doped GaAs/AlGaAs multiple quantum well (MQW) structure on patterned (111)A GaAs substrates. The optical properties of the MQW on a (311)A sloped surface and a (111)A flat surface are evaluated by cathodoluminescence. We confirm the subband formation and lateral p-n junctions for Si delta-doped MQWs. The LSJ shows good current-voltage properties when forward currents are injected into it. A recombination emission (791 nm) with an energy level higher than the band gap of bulk GaAs is observed at 300 K; this clearly shows that the potential bending occurs between n-type subbands and p-type subbands. The rise time of light-emitting diodes (LED) with the LSJ (LSJ-LED) is below 5 ns (>200 MHz). The LSJ has a high potential for applications in optical devices.