Customized Filter Cube in Fluorescence Microscope Measurements of InGaN/GaN Quantum-Well Characterization

Modified optical filter elements were fabricated to access blue and violet spectral ranges of InGaN/GaN light-emitting diodes (LEDs) in characterizing luminescence via a fluorescence microscope. As band gap energies of GaN and InGaN layers were close, it was not trivial to separate excitation and luminescence light, which caused slight detection of excitation light. Nevertheless, the results obtained on c - and m -plane LEDs were compared with our previous work, leading consistent understanding of luminescence characteristics in terms of the quantum-confined Stark effect.