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We tried to fabricate a quaternary N-rich GaInNP multiple quantum well (MQW) structure to obtain a blighter emission of a LED. The GaInNP was grown using laser-assisted metalorganic chemical vapor deposition (LAMOCVD). The growth temperature was 950 °C. A pulsed ArF (193 nm) was also applied for the growth. The laser power was 0.1 J × 100 Hz. A sapphire substrate was used for the growth. A p-GaN/ (undoped GaN/GaInNP, 3 pair)/n-GaN/GaN buffer/sapphire structure was grown using LAMOCVD. A GaInNP MQW structure LED was fabricated. Pt/Au was used for a p-electrode and Al/Ti/Au was used for an n-electrode. The electroluminescence (EL) of the LED was measured. Sharp and bright 435 nm emissions were obtained. The EL intensity of a GaInNP MQW LED was stronger than that of a GaNP single quantum well (SQW) LED. A GaInNP MQW-structure LED was thus demonstrated for the first time. IntroductionThe III-N-V type alloy is a very unique material, since it has been theoretically predicted to have huge bandgap bowing. These alloys have been estimated to have a potential to cover a very wide wavelength region from ultraviolet to infrared. GaNAs and GaNP alloys are therefore expected to realize emissions of visible multi-wavelengths, since these materials should have gigantic bandgap bowing [1 -11]. Nitride-rich (N-rich) hexagonal GaNPs grown by gas-source molecular-beam epitaxy (GSMBE) [5,6] and metalorganic chemical vapor deposition (MOCVD) [7,10,11] have recently been reported. However, reports concerning the photoluminescence (PL) of N-rich GaNP have very few. That is, visible-light emission based on the band-edge of GaNP has not yet been reported. Especially, a GaNP crystal with a composition ratio (x) of about 2% was obtained, as determined by Xray diffraction. That is, the PL emission of GaNP could not observed, since the grown crystals were poor, and optical properties of this alloy were only reported using P ion-implanted GaN with a P concentration of 10 17 -10 18 cm -3 [12,13], or GaNP with a lower composition ratio (x), since a high-quality GaNP with a composition ratio (x) of over 1% was not obtained using MOCVD or MBE. A serious problem is that GaNP has a very large miscibility gap, resulting in difficult GaNP growth. We have already reported that GaNP with a high P concentration of about 10% was grown using laser-assisted metal organic chemical vapor deposition (LAMOCVD). Using this LAMOCVD, a higher growth rate (20 µm/h -30 µm/h) of GaN was obtained. We have already reported a GaNP single quantum well (SQW) structure LED. A bright 425 nm light emission was observed, although a weak yellow emission was also observed [14,16].In this work, we furthermore improved the apparatus of LA-MOCVD in order to obtain high-quality GaN 1-x P x with a larger composition ratio (x). We report on the GaNP growth results and that a GaInNP multiple quantum well (MQW) blue-violet LED was performed for the first time.

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