Extended electron states in lateral quantum dot molecules investigated with photoluminescence

Optical anisotropy in self-assembled InAs nanostructures grown on GaAs high index substrate

“…This behavior may be attributed to the contribution of the excited states in the PL spectra 8 (or=and) to the tunnel electronic coupling between neighboring quantum dots. 27 As shown in Fig. 1(c), the S3 spectrum is well fitted by three Gaussian curves with peak position of 1.238, 1.325, and 1.390 eV those denoted by P1, P2, and P3, respectively.…”

Today's challenges in quantum dot materials research for tomorrow's quantum functional devices

“…This is in marked contrast to other methods for QD ordering relying directly on the preferential nucleation of QDs induced on patterned substrates or by steps, which easily introduces defects in the QDs due to roughness and disorder on the nanoscale [40][41][42]. Excitation power density dependent PL measurements of ensembles of ordered InAs QD molecules on GaAs(311)B reveal the presence of extended states due to lateral electronic coupling of the QDs within the molecules [15]. Figure 7 shows the evolution of the PL spectra taken at 5 K of the QD molecules with an average of (a) 4 and (b) 8 QDs per molecule upon increasing the excitation power density.…”

“…Linear QD arrays are formed on GaAs(100) [10][11][12] while a lattice of ordered lateral QD molecules is realized on GaAs (311)B substrates [13,14]. Excitation power and temperature dependent photoluminescence (PL) measurements indicate lateral electronic coupling of the QDs within the QD molecules [15].…”

Formation of Lateral Low Density In(Ga)As Quantum Dot Pairs in GaAs Nanoholes

“…According to previous studies in similar systems, the differences found between both samples could also be related to carrier tunneling involving charge redistribution between the QD in the pairs. 22,23 These PL results related to emission line shape dependence with excitation power and fwhm evolution with T can then be considered as preliminar signatures of lateral coupling in the QD pairs. However, to this respect, further optical studies at the individual QD pair level are mandatory to firmly establish the existence of QD molecules in this system.…”

“…The photoluminescence (PL) emission of the QD pairs, in particular the evolution of the peak energy and full width at half-maximum (fwhm) as a function of excitation intensity and temperature respectively, show signatures of laterally coupled quantum systems 21 as has been previously reported. 22,23 …”