High-performance AlGaInP/GaAs light-emitting diodes with a carbon-doped GaP/indium-tin oxide contact layer

Abstract

An alternative heavily carbon-doped GaP (GaP:C) contact layer is demonstrated to format good ohmic contact to electronbeam-evaporation indium-tin oxide (ITO) spreading layer on the AlGaInP light-emitting diode (LED) with a GaAs absorbing substrate. The LEDs with GaP:C/ITO contact layer provide a substantial improvement in light output power over conventional structures (without GaP:C/ITO). The AlGaInP LEDs with GaP:C/ITO structures exhibited :l higher external quantum efficiency (3.24%) and larger light output power (5.9mW) under a de operation of 160mA than those of 2.01% and 1.93 mW at 120 mA for the conventional structures, showing an earlier saturation behavior of current-power characteristics. These positive results are tentatively attributed to the introduction of the GaP:C/ITO current-spreading structures in the LEDs.