How numerical simulations can advance wide bandgap materials and devices: a case study on the optical spectrum of visible light-emitting diodes*

Numerical simulations can help accelerate the development of wide bandgap materials and devices by bringing unique insights that are otherwise inaccessible by experiments alone. A paradigmatic example of wide bandgap semiconductor technology that can be found in nearly every U.S. household today is the visible light-emitting diode (LED) based on InGaN semiconductors. Despite their success, the color purity of green and longer wavelength InGaN LEDs severely degrades at high operating currents, thus limiting their utility to low-power applications. In this work, we show how our combined theoretical and experimental study has helped resolve the mystery of why the color purity of InGaN LEDs degrades at high operating currents. This has led to new insights on device designs that improve the high-power color purity of visible LEDs. In light of this success, we discuss how our multi-scale modeling approach can be generalized to accelerate advances in emerging wide bandgap optoelectronic and photovoltaic technology.