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

We demonstrate light-emitting diodes, a vertical-cavity surface-emitting la ser (VCSEL), and a photodiode fabricated using a lateral p-n junction. The lateral p-n junction is formed in a GaAs-silicon doped layer grown by molec ular-beam epitaxy on a patterned GaAs (311)A-oriented substrate. Lateral p- n junctions have particular properties (i.e., small junction area, coplanar contact geometry, can be clad between electrically insulating layers, allo w carrier transport in the plane of multilayer structures, etc.) that are p romising for application in new devices. Light-emitting diodes exhibit good electroluminescence at room temperature for both GaAs single layers and Ga As-AlGaAs multiple-quantum-well structures. The VCSEL has electrically insu lating distributed Bragg reflectors and coplanar contacts which simplify th e device Fabrication process. Pulsed-mode operation at room temperature was obtained with a threshold current of 2.3 mA. The light-emission spectrum h as a single peak at 942 nm with a full-width at half-maximum of 0.15 nm, Th e photodiode design allows a reduction of the junction capacitance and an i ncrease of the response speed. A nonoptimized device exhibited a time const ant of 10 ps.