Lateral junctions for high-density integration of optoelectronic devices

Abstract

Lateral p–n junctions are made by molecular-beam epitaxy (MBE) on patterned GaAs (3 1 1)A substrates using the amphoteric properties of silicon (Si) as a dopant impurity for different GaAs surface orientations. Lateral p–n junctions are interesting for application in optoelectronic devices due to a reduced junction area, direct injection of carriers in the active layer, and ease of interconnections due to their coplanar geometry. We fabricated arrays of lateral-junction LEDs with device densities of 1200 and 2400 dots-per-inch (dpi). The devices were fabricated on patterned GaAs (3 1 1)A substrates. Multilayer structures including InGaAs/GaAs quantum wells or AlGaAs active layers were grown by MBE. Electroluminescence spectra at room temperature showed peaks for wavelengths ranging from λ=670 to 960 nm , depending on the composition of each device's active layer. Results obtained with these lateral-junction devices are promising for application in LED arrays for printers.