[TuP3A] Epitaxy and process

[TuP3A-20] Quantum Well Width Dependence of Photoluminescence from InGaAs/GaAsSb Type-II Quantum Well on GaAs Substrate

〇Hikaru Nakano¹, Tomoki Funaki¹, Takeshi Fujisawa², Koji Maeda¹, Masakazu Arai¹ (1. Univ. of Miyazaki (Japan), 2. Hosei Univ. (Japan))

Optical coherence tomography (OCT) requires broadband light sources, such as superluminescent diodes (SLDs), for high-resolution imaging of biological tissues. In this study, we investigated InGaAs/GaAsSb Type-II quantum wells (QWs) grown by metalorganic vapor phase epitaxy (MOVPE) as a novel broadband active medium. We fabricated samples with varying well widths from 3 to 6 nm and evaluated their photoluminescence (PL) characteristics at room temperature. The results showed that the spectral width is strongly dependent on the well width and excitation intensity. Notably, the sample with a 5 nm well width exhibited the largest full width at half maximum (FWHM), which is attributed to enhanced emission from higher-order quantum levels. Experimental spectra showed excellent agreement with theoretical calculations, suggesting that Type-II heterostructures are promising candidates for high-performance broadband light sources.