Shallow Trap Dynamics and Non-Thermal Spectral Shift in Sub-10‑μm InGaN Micro-LEDs

Miniaturized InGaN micro-LEDs suffer reliability drifts that are not fully captured by conventional optical/electrical reporting. This study shows that, after 500-hour direct current (DC) operation at 40 Acm−2 , sub-10-µm devices exhibit a dominant-wavelength red shift under fixed current that is non-thermal, as veriffed by ＜ 0.5℃ infrared thermography. A capacitance-decomposition model resolves the measured capacitance-voltage (C-V) dispersion into physically distinct trap ensembles and yields sub-40-ns response times, identifying shallow, sidewall-related traps as primary actors. The extracted trap dynamics quantitatively account for the increased series resistance, efficiency peak suppression, and weakened quantum-confined Stark effect (QCSE) screening responsible for the spectral shift. These results establish a mechanism-driven picture of reliability in miniaturized InGaN emitters and provide a general methodology for trap-dynamics quantiffcation in wide-bandgap optoelectronics. A display-driving implication is briefly noted, with details in the Supplementary Material.