Study of Deep Ultraviolet Light-Emitting Diodes with a p-AlInN/AlGaN Superlattice Electron-Blocking Layer

Abstract

The AlGaN-based deep ultraviolet light-emitting diodes with a p-type Al 0.92 In 0.08 N/Al 0.55 Ga 0.45 N superlattice electron-blocking layer are studied numerically. The energy band diagrams, radiative recombination rate, electron leakage current, light output power and internal quantum efficiency are investigated. The simulation results show the structure has a low electron leakage current and high hole injection efficiency compared to the original deep ultraviolet light-emitting diodes, which is ascribed to the deep ultraviolet light-emitting diodes with a p-type Al 0.92 In 0.08 N/Al 0.55 Ga 0.45 N superlattice electron-blocking layer having a low polarization effect on the interface between the last quantum barrier and the electron-blocking layer. As a result, the radiative recombination rate and the light output power are significantly enhanced.

Physical and technological analysis of the AlGaN-based UVC-LED: an extended discussion focused on cubic phase as an alternative for surface disinfection.

“…However, high Al content drawbacks in design. To solve this, some approaches have been studied such as p-type electron blocking layer (p-EBL), p-EBL superlattices, and graded superlattices [128][129][130][131][132]. By applying an EBL with an SL structure, the effective barrier height at the valence band is decreased.…”

On the Hole Injection for III-Nitride Based Deep Ultraviolet Light-Emitting Diodes

“…It is unambiguous that the hole injection across the p-EBL can be improved once the valence band barrier height for the p-EBL decreases. For that purpose, it is advisable to relocate the superlattice structure to the p-EBL region to form the superlattice p-EBL [ 77 , 78 ]. Another strategy to increase the hole injection is to facilitate the hole tunneling process, which can be realized by reducing the thickness for the p-EBL while increasing the AlN composition for the p-EBL, e.g., using the AlN based p-EBL with a properly small thickness [ 79 ].…”

Performance enhancement with thin p-AlInN electron-blocking layer in ultraviolet light-emitting diodes

“…[16][17][18][19] The lattice mismatch between AlInN lattice and AlGaN is low, which reduces piezo polarization at heterointerfaces. 17,20 The band offset of AlInN, in comparison to AlGaN, also favors efficient carrier confinement. 19,21 Inspired by these features of AlInN, we propose AlInN electron-blocking layer (EBL) in this work.…”

“… – 15 AlN and AlInN are the potential alloys that have been used by many research groups for the development of efficient optoelectronic devices 16 – 19 The lattice mismatch between AlInN lattice and AlGaN is low, which reduces piezo polarization at heterointerfaces 17 , 20 . The band offset of AlInN, in comparison to AlGaN, also favors efficient carrier confinement 19 , 21 .…”