Study of an AlGaInP-Based Light-Emitting Diode With a Modulation-Doped Multiquantum-Well (MD-MQW) Structure

An AlGaInP-based multiquantum-well (MQW) light-emitting diode (LED) with an n-type modulation-doped (MD) structure, grown by metal-organic vapor-phase epitaxy, is fabricated and studied. Experimental results indicate that a lower turn-on voltage and dynamic resistance, higher output power, and smaller wavelength shift, as compared to a conventional undoped-MQW LED, are obtained. The studied n-type MD-MQW LED also exhibits a higher external quantum efficiency of 7.2% and a larger maximum light output power. The junction temperature of the studied MD-MQW LED also shows a 12 degC reduction, at 200 mA, as compared to a conventional one. These positive results are mainly attributed to the presence of a higher electron concentration in the MD-MQW active region.