The effects of quantum dot coverage in InAs/(In)GaAs nanostructures for long wavelength emission

Comparative Study of Photoelectric Properties of Metamorphic InAs/InGaAs and InAs/GaAs Quantum Dot Structures

“…The metamorphic InAs/InGaAs QD structure consists of (i) 0.1 μm n + -GaAs buffer layer grown at 600 °C, (ii) 300 nm thick n + -doped In 0.15 Ga 0.85 As MB with n  = 5 × 10 18  cm −3 grown at 490 °C, (iii) 500 nm thick n -doped In 0.15 Ga 0.85 As MB with n  = 3 × 10 16  cm −3 grown at 490 °C, (iv) 3.0 monolayers of self-assembled InAs QDs on a WL grown by atomic layer MBE (ALMBE) at 460 °C embedded in the middle of a 20 nm undoped In 0.15 Ga 0.85 As layer, (v) 300 nm n -doped In 0.15 Ga 0.85 As upper capping layer with n  = 3 × 10 16  cm −3 grown at 490 °C, and (vi) 13 nm p + -doped In 0.15 Ga 0.85 As cap with p  = 2 × 10 18  cm −3 grown at 490 °C (Fig. 1) [4, 15]. As discussed in Ref.…”

InAs/GaAs quantum dot density variation across a quarter wafer when grown with substrate rotation

“…The QD density depends on several growth parameters, such as InAs coverage [5,6,10], InAs growth rate [5,7], As-flux [3,8] and substrate temperature [2,3,9]. The QD density variation observed in our samples could thus in principle be caused by variation in any of these parameters across the wafer.…”

“…Earlier works have shown how the MBE growth parameters strongly influence the quantum dot properties, see e.g. [2][3][4][5][6][7][8][9][10][11].…”

Effects of growth parameters on the surface morphology of InAs quantum dots grown on GaAs/Ge/Si1−xGex/Si substrate

“…The influence of InAs coverage on the InAs QDs grown on GaAs substrates has been reported [20,21]. In summary, the effects of InAs coverage can be classified into 4 different regimes: (1) at low InAs coverage (0-1.7 ML), the QDs are yet to be formed; (2) when the InAs coverage exceeds a critical value ( $ 1.7 ML), the QD density increases abruptly; (3) as the InAs coverage continues to increase, the QD density and QD dimensions first increase in a gradual manner and then saturate and (4) eventually, the QD density decreases and the dot width increases when dot coalescence occurs.…”