15:15 〜 15:30
▼ [22p-D316-9] Investigation of an additional point-like short-wavelength emission in InGaN red light-emitting diodes
キーワード：InGaN, Light emitting diode, Multi-microscopy
Indium gallium nitride (InGaN) is a popular material for the light-emitting diodes (LEDs) fabrication. With different In-content in the InGaN alloy, the material bandgap varies from 0.67 to 3.42 eV. The low-In content blue LEDs are reaching up to 84% external quantum efficiency and are widely used as a light source. However, InGaN-based LEDs with longer emission wavelength demonstrate much lower efficiencies. High In-content in the active region also often results in appearance of the additional short-wavelength emission.
We fabricated InGaN-based red LED with peak emission of 649 nm and a noticeable additional short-wavelength emission at 465 nm. We investigated the LED electroluminescence (EL) spectra behavior under various injection conditions which helped to understand defect-related nature of the charge carriers’ injection into the additional emission point-like sources. Using multi-microscopy methods, we precisely determined the positions of additional emission sources in relation to the surface defects. We revealed that short-wavelength additional emission corresponded to the vicinity of surface defects using the energy-dispersive X-ray spectroscopy in STEM observation.
These results are helpful to understand red InGaN LEDs emission behavior and can help to improve the efficiency of such devices in the future.
We fabricated InGaN-based red LED with peak emission of 649 nm and a noticeable additional short-wavelength emission at 465 nm. We investigated the LED electroluminescence (EL) spectra behavior under various injection conditions which helped to understand defect-related nature of the charge carriers’ injection into the additional emission point-like sources. Using multi-microscopy methods, we precisely determined the positions of additional emission sources in relation to the surface defects. We revealed that short-wavelength additional emission corresponded to the vicinity of surface defects using the energy-dispersive X-ray spectroscopy in STEM observation.
These results are helpful to understand red InGaN LEDs emission behavior and can help to improve the efficiency of such devices in the future.