Tunable wavelength hot electron light emitter

We demonstrate the operation of a surface emitting light emitting diode. The wavelength of the emitted light can be tuned with the applied voltage. The device is based on a p‐GaAs and n‐Ga1−xAlxAs heterojunction containing an inversion layer in the p side and, GaAs quantum wells in the n side, and, is referred to as HELLISH‐II (hot electron light emitting and lasing in semiconductor heterojunction). The device utilizes hot electron longitudinal transport and, therefore, light emission is independent of the polarity of the applied voltage.