Nanoscale imaging of reduced forward bias at -shaped defects in nitride-based green LEDs
Phys. Rev. Applied 26, 014014 – Published 7 July, 2026
DOI: https://doi.org/10.1103/x3kp-7nqg
Abstract
Record wall-plug efficiencies in long-wavelength, III-nitride light-emitting diodes (LEDs) have recently been achieved through improvements in electrical efficiency in devices containing V-defects. Numerical modeling suggests this may be due to reduced barrier heights for charge injection in thinned, low-Indium quantum wells parallel to semipolar V-defect facets. To test this proposition, the tip of a scanning tunneling luminescence microscope is used as a local hole injector to map the optoelectronic properties of commercial, green-emitting LED heterostructures around V-defects with nanoscale spatial resolution. A 1 V reduction in the forward bias necessary for current injection at V-defect rims is observed. This, combined with the observation of small (approximately 10 meV) blue shifts in the locally emitted electroluminescence, unambiguously confirms the charge injection mechanism.
