Optoelectronic devices based on lateral p-n junctions fabricated bymolecular-beam epitaxy growth of silicon-doped GaAs on patterned(311)A-oriented substrates

摘要

We demonstrate light-emitting diodes, a vertical-cavitynsurface-emitting laser (VCSEL), and a photodiode fabricated using anlateral p-n junction. The lateral p-n junction is formed in anGaAs-silicon doped layer grown by molecular-beam epitaxy on a patternednGaAs (311)A-oriented substrate. Lateral p-n junctions have particularnproperties (i.e., small junction area, coplanar contact geometry, can benclad between electrically insulating layers, allow carrier transport innthe plane of multilayer structures, etc.) that are promising fornapplication in new devices. Light-emitting diodes exhibit goodnelectroluminescence at room temperature for both GaAs single layers andnGaAs-AlGaAs multiple-quantum-well structures. The VCSEL has electricallyninsulating distributed Bragg reflectors and coplanar contacts whichnsimplify the device fabrication process. Pulsed-mode operation at roomntemperature was obtained with a threshold current of 2.3 mA. Thenlight-emission spectrum has a single peak at 942 nm with a full-width atnhalf-maximum of 0.15 nm. The photodiode design allows a reduction of thenjunction capacitance and an increase of the response speed. Annonoptimized device exhibited a time constant of 10 ps