Broad-band electroluminescence from highly stacked InAs quantum dot at telecom-band

We have developed a growth procedure for increasing the number of stacked layers of InAs quantum dots (QDs) on an InP(311)B substrate that is resistant to defects and dislocations. In this work, we also developed a modulated stacking structure consisting of various size QDs for electroluminescence (EL). This promotes broad-band emission because each QD-distributed wide range can emit a different wavelength. The EL spectrum of this sample was measured with pulsed current injection. There was a strong emission from the ground state at approximately 1524 nm which is suitable for fiber-optic communications, with an injection current of 100 mA at room temperature. The full width at half maximum was 213 nm. Modulated stacking using this strain-compensation technique is thus a useful way to expand the gain wavelength.