InAs/InP QDs broadband LED using selective MOVPE growth and double-cap procedure

Flat-Topped Emission with Spectral Width above 500 nm from InAs/InP Quantum Dot Waveguide Array Light-Emitting Diode

“…For example, a fiber supercontinuum source for OCT with a center wavelength of 1.7 m and a bandwidth of 358 nm has been demonstrated. 1) As semiconductor broadband spectrum emission devices, we have fabricated selfassembled Stranski-Krastanov (SK) InAs/InP quantum dot (QD) 2,3) light-emitting diodes (LEDs) with a bandwidth of more than 400 nm by selective metal organic vapor phase epitaxy (MOVPE) using a double-capping procedure to control the size of the QDs. 4,5) The QDs have a threedimensional carrier confinement structure, and the QD size can be used to control the in-plane band gaps to obtain broadband spectral emission.…”

Selective MOVPE growth of InAs QDs using double-cap procedure

“…Layer by layer control of the multi stacked QD energy was achieved by changing the height of the QDs using the double-cap procedure, and the strain energy in the QDs was varied by compositional change of the GaInAs buffer layer under the QDs. A spectrum width of more than 400 nm was obtained from this LED device [4,5]; however, the output power from the QDs on the high tensile strain buffer layer was very weak and the spectrum width was not as broad as expected. To overcome this problem, the height of the QDs was changed and the Ga content in the GaInAs layer was limited to 0.4770.1 to decrease the reduction emission intensity with the large strain buffer layer, and a broader spectrum width was obtained.…”

“…Fig. 6(a) shows the PL spectrum for QDs from arrays #1 and #16 from the previous studies [4,5], and (b) shows the PL spectrum for arrays #1, #8 and #16 from this work. The FCL thickness of Ga 0.47 In 0.53 As was 3 nm in the previous work and 2.5 nm in this work; therefore, the peak wavelength was blue-shifted due to the reduction of the QD height.…”

“…In the previous work, 3 QD layer LED devices were fabricated with respective FCL thicknesses and Ga contents in the GaInAs buffer layer [4,5]; the 1st QD layer were 3 nm and 0.47, the 2nd QD layer was 1.5 nm and 0.7, and the 3rd QD layer was 4.5 nm and 0.3, respectively. A spectrum width of more than 400 nm was obtained under the continuous wave (CW) electric current injection.…”

“…We have previously reported InAs/InP QD broadband light emitting diodes (LEDs) grown by selective metalorganic vapor phase epitaxy (MOVPE) using the double-cap procedure [3][4][5]. To obtain in-plane energy level control of QDs, selective MOVPE growth was performed using an asymmetric array waveguide pattern [6][7][8].…”