VCSEL structure hot electron light emitter

The hot electron light emitting and lasing semiconductor heterostructure vertical cavity surface emitting lasers (VCSELs) are devices that utilise hot carrier transport parallel to the layers of the GaxAl1−xAs p–n junction. The junction contains a GaAs quantum well (QW) in the depletion region. The fabrication of these devices is very simple, and requires only two top contacts that are diffused throughout the heterolayers. Light emission, being a hot carrier effect, is independent of the polarity of the applied bias. Pulsed operation of the device as a VCSEL has already been demonstrated at room temperature. An output power of 5.5 mW in a single longitudinal mode has been obtained. The doping and other structural parameters can be optimised for efficient injection of hot electron–hole pairs into the QW. In this work, we report our reflectivity, electroluminescence, and photoluminescence studies at room temperature. We also present the experimental results of emitted power measured as a function of the applied electric field.