Removal of hydrogen by electric and polarized fields for high-performance AlGaN deep-ultraviolet-C light emitting diodes

The dehydrogenation of the Mg–H complex to increase the hole concentration is crucial for promoting the performance of ultraviolet-C light-emitting diodes (UVC-LEDs). Here, we systematically investigate the efficient removal of H atoms through combining external electric field produced by electrochemical process and polarized electric field of p-AlGaN. The measured electroluminescence spectra show the emission intensity of optimized AlGaN structure achieving a large increment of 12.5% after the H removal. Furthermore, the reliability and lifetime of UVC-LEDs are also significantly promoted by our methods. The physical mechanism of the coupling interaction between external and polarized electric fields on H removal is further elucidated through the first-principles calculations. The density of states, electrostatic potential energies, and differential charge densities of Mg–H doping AlGaN under various electric fields reveal that the charge redistributions and huge electrostatic potential difference between Mg and H atoms are responsible for the breaking of Mg–H bonds and expelling of H atoms. This work offers feasible strategy to promote the applications of AlGaN-based UVC-LEDs.