Sandwiching electron blocking layer with p-AlInN layer to enhance hole injection in AlGaN-based deep ultraviolet light-emitting diodes

This work reports the enhanced optoelectronic performance of AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) by sandwiching p-EBL with thin p-AlInN layers. The simulated results show that the internal quantum efficiency (IQE) and radiative recombination rate are remarkably improved as compared to conventional AlGaN-based p-EBL. The primary cause of this enhancement is the reduction of lattice mismatch between the electron blocking layer (EBL) and p-AlGaN due to the insertion of thin p-AlInN layers, which ultimately decreases the polarization effect. Moreover, p-AlInN layers also improved the hole injection efficiency via intra-band tunneling while hindered the electron leakage to the p-type layer. Interestingly, the proposed structure not only increased the IQE but also suppressed the efficiency droop dramatically.