Green InGaN/GaN LEDs: High luminance and blue shift

摘要

We report in this paper electro-optical results on InGaN/GaN based green micro light-emitting diodes (μLEDs). Currentlight-voltage measurements reveal that the external quantum efficiency (EQE) behavior versus charge injection does notfollow the ABC model prediction. Light-emission homogeneity investigation, carried out by photoluminescencemapping, shows that the Quantum Confinement Starck Effect (QCSE) is less significant at the edges of μLEDs.Electroluminescence shows a subsequent color green-to-blue deviation at high carrier injection levels. The extractedspectra at different current injection levels tend to show the appearance of discrete wavelength emissions. Theseobservations may enhance the hypothesis that higher-energy excited-levels in InGaN quantum wells may also contributeto the blue shift, solely attributed to QCSE lessening under intense electric field magnitudes. We hereby present firstresults dealing with green μLEDs electro-optical performances with regards to their size.