GaN-Based Dual-Color LEDs With p-Type Insertion Layer for Controlling the Ratio of Two-Color Intensities

In this paper, a novel GaN-based dual-color LED for phosphor-free white-light generation has been demonstrated. By inserting p-type layers with different p-type doping density and thickness into active regions of dual-color GaN LEDs, we can control the ratio of output light intensities from quantum-wells near n- and p-sides. With an optimum sheet charge density of such insertion layer, the intensities of these two colors can be balanced under a much lower driving-current density (45 versus 450 A/cm²) compared with that of reference device without such insertion layer. A 2-D finite-element Poisson and drift-diffusion self-consistent solver including the indium fluctuation is used to design and simulate the device performances. The experimental and simulation results match very well.