  The undoped BAlN electron-blocking layer (EBL) is investigated to replace the
conventional AlGaN EBL in light-emitting diodes (LEDs). Numerical studies of
the impact of variously doped EBLs on the output characteristics of LEDs
demonstrate that the LED performance shows heavy dependence on the p-doping
level in the case of the AlGaN EBL, while it shows less dependence on the
p-doping level for the BAlN EBL. As a result, we propose an undoped BAlN EBL
for LEDs to avoid the p-doping issues, which a major technical challenge in the
AlGaN EBL. Without doping, the proposed BAlN EBL structure still possesses a
superior capacity in blocking electrons and improving hole injection compared
with the AlGaN EBL having high doping. This study provides a feasible route to
addressing electron leakage and insufficient hole injection issues when
designing UV LED structures.
