740-nm emission from InGaN-based LEDs on c-plane sapphire substrates by MOVPE

We have realized for the first time deep-red emission from InGaN-based light-emitting diodes on c-plane sapphire substrates grown by metalorganic vapor-phase epitaxy. The peak wavelength was 740 nm by continuous current injection, in spite of a wide full-width at half-maximum. Indium incorporation was enhanced by a smaller distance of the opposing wall of the reactor from the susceptor, which resulted in raising the gas temperature. In addition, a higher number of quantum wells led to the relaxation of InGaN well layers and thus enhanced indium incorporation.

► We realized deep-red emission from InGaN-based LEDs on c-plane sapphire substrates. ► The electroluminescence peak wavelength was 740 nm, in spite of a wide FWHM. ► Indium incorporation was enhanced by a smaller distance of the reactor. ► A number of quantum wells led to the relaxation of InGaN wells and higher In content.