High-efficiency cryogenic temperatures yellow quantum dot for light emitting diodes

Light emitting III-V materials have shown a severe reduction in efficiency for wavelengths in the range 550-590 nm in both InGaN and AlInGaP compounds. Quantum dot (QD) based active layer could afford the promise to solve some of these limitations, providing an interesting route towards high performance optoelectronic devices emitting in the yellow band. Here we investigate the photoluminescence properties of multilayered AlInP/AlInGaP QD system emitting at ~580 nm (at 10 K). The small AlInP QD size (1-2 MLs) and the investigation of different AlInGaP barrier composition allowed to stack a large number of QD layers (>100) with an optimized radiative recombination efficiency. Most importantly, the temperature-dependent internal quantum efficiency outperformed a comparable AlInGaP quantum well system at temperatures below 180 K. This interesting result demonstrates the potential hold by QD systems and depicts interesting perspective for light emitting diode applications.