A New Carrier Transport Model for Light Emitting Devices with Quantum Well

Abstract

We present a new carrier transport model for light emitting devices with quantum well. These devices include light emitting diodes (LEDs) and laser diodes (LDs). Nearly all LDs and high efficient LEDs in production contain a quantum well (QW) or multi-quantum well (MQW) in a PN junction. When these devices are driven to produce light, large number of carries, electrons and holes, are injected into the QW. The electrons and holes are expected to recombine completely in the QW. The electrons and holes are not supposed to transport over the QW and reach the opposite side. The transport action in light emitting devices is different from that in a typical PN junction without QW, where most carriers transport to the other side without recombination. Thus, the Sah-Noyce-Shockley (SNS) model for a PN junction without QM cannot be applied to light emitting devices with QW. In this study, current-voltage curves calculated using the new model agree well with results measured on GaN/sapphire LEDs with InGaN quantum wells. Junction temperature Tj rather than case temperature Tc is used to achieve better agreement.