Design of p-type cladding layers for tunnel-injected UV-A light emitting diodes

We discuss the engineering of p-AlGaNcladding layers for achieving efficient tunnel-injected III-Nitrideultraviolet light emittingdiodes(UVLEDs) in the UV-A spectral range. We show that the capacitance-voltage measurements can be used to estimate the compensation anddoping in the p-AlGaN layers located between the multi-quantum well region and thetunnel junction layer. By increasing the p-typedoping concentration to overcome the background compensation, on-wafer external quantum efficiency and wall-plug efficiency of 3.37% and 1.62%, respectively, were achieved for the tunnel-injectedUVLEDs emitting at 325  nm. We also show that interbandtunneling hole injection can be used to realizeUVLEDs without any acceptordoping. The work discussed here provides new understanding of holedoping and transport in AlGaN-basedUVLEDs and demonstrates the excellent performance of tunnel-injectedLEDs for the UV-A wavelength range.

Source: Applied Physics Letters - November 9, 2016 Category: Physics Authors: Yuewei Zhang, Sriram Krishnamoorthy, Fatih Akyol, Andrew A. Allerman, Michael W. Moseley, Andrew M. Armstrong and Siddharth Rajan Source Type: research