Stranski-Krastanov Growth of InAs Quantum Dots with Narrow Size Distribution

Abstract

Coherently strained InAs quantum dots (QDs) with narrow inhomogeneous broadening were grown by molecular beam epitaxy (MBE) using the Stranski-Krastanov (SK) growth mode. The increase in the InAs dot size and decrease in the dot density were induced by surface migration enhancement due to the low arsenic pressure below 6×10-7 Torr. In addition, the low arsenic pressure and the low growth rate produced the self size-limiting effect, which was attributed to the inhibition of indium incorporation. As a result, the narrowest photoluminescence (PL) linewidth of 18.6 meV (14 K) was successfully obtained from the single InAs/GaAs QD layer.

Gain and Threshold Current in Type II In(As)Sb Mid-Infrared Quantum Dot Lasers

“…Unlike the common Stranski-Krastanov growth of QDs, which mainly relies on the strain effect between the deposited material and the substrate [11], in this case the growth of the InSb QDs is based on the As-to-Sb anion exchange reaction, which is achieved by exposing the substrate to Sb2 flux for a very short time interval. The substrate temperature during dot formation can be adjusted in the interval 320-450 °C , resulting in InSb layers of thickness in the range 0.5-0.9 monolayer (ML).…”

Nanophotonic Devices Based on Semiconductor Quantum Nanostructures

“…The threshold current density for each QD layer of our proposed QD laser was 18.2 A/cm 2 /layer. Moreover, the threshold current density for each QD in our proposed QD laser exhibited a lower value of 2.7 × 10 In this study, we fabricated high-performance QDs with a high density of 1×10 11 cm −2 and a narrow PL FWHM of 22.3 meV using As 2 , a graded strain-reducing layer, and a molecular beam at 1.3 μm. We determined optical properties of the active layer composed of high-density and highuniformity QDs.…”

Critical cluster size of InAs quantum dots formed by Stranski–Krastanow mode

“…Although the size of islands is known to be limited automatically in S-K mode, the effect occurs only in large islands of which diameter is about 30 nm or longer. 22 The effect should not be notable in nucleation because a critical cluster consists only of a few atoms, as discussed later. The adatom density may increase because adatoms cannot attach to large islands due to the self-size-limiting effect; the island density is generally a function of adatom density.…”