Coupled strained-layer InGaAs quantum-well improvement of an InAs quantum dot AlGaAs–GaAs–InGaAs–InAs heterostructure laser

Abstract

Data are presented showing that, besides the improvement in carrier collection, it is advantageous to locate strain-matching auxiliary InGaAs layers ͓quantum wells ͑QWs͔͒ within tunneling distance of a single-quantum-dot ͑QD͒ layer of an AlGaAs-GaAs-InGaAs-InAs QD heterostructure laser to realize also smaller size QDs of greater density and uniformity. The QD density is changed from 2ϫ10 10 /cm 2 for a 50 Å GaAs coupling barrier ͑QW to QD͒ to 3ϫ10 10 /cm 2 for a 5 Å barrier. The improved QD density and uniformity, as well as improved carrier collection, make possible room-temperature continuous-wave ͑cw͒ QDϩQW laser operation ͑a single InAs QD layer͒ at reasonable diode length ͑ϳ1 mm͒, current density 586 A/cm 2 , and wavelength 1057 nm. The cw 300 K coupled InAs QD and InGaAs QW AlGaAs-GaAs-InGaA-InAs heterostructure lasers are grown by metalorganic chemical vapor deposition.

LP-MOVPE growth of InAs quantum dots using tertiarybutylarsine (TBA) in pure N2 ambient

“…At lower TMIn inlet flow, thinner InAs layer was deposited. The shape is same as that grown by MOVPE in hydrogen ambient [8]. Because the thermal conductivity and heat capacity of nitrogen are higher than that of hydrogen, the cooling rate of MOVPE reactor in nitrogen ambient is faster.…”

The effect of a combined InAlAs and GaAs strained buffer layer on the structure and optical property of InAs quantum dots

“…However, the InGaAs potential barriers used in these techniques result in a reduction of energy separation between discrete energy levels of QDs. Furthermore, few reports have concentrated to the crystal growth mechanisms about the increment of dot density [15].…”

Electronic Structure Calculations of InP-Based Coupled Quantum Dot-Quantum Well Structures

“…In an attempt to deal with these problems, the QD laser has recently been modified into a QD-QW laser via tunnel-injection of electrons from the QW into the QDs, which was proposed in Refs. [4] and [5]. Such a tunnel-injection QD laser has indeed shown an enhanced small-signal modulation bandwidth and reduced temperature sensitivity of the threshold current density.…”