Raman study of optical phonons in ultrathinInAs∕InPsingle strained quantum wells

Optical emission from InAs/InP self-assembled quantum dots: evidence for As/P intermixing

“…However, the QW width assigned to the PLE resonances of the samples with d XRD < d c differs by one ML from that reported in [28]. The present assignment is firmly supported by a determination of the InAs epilayer thickness in the same samples from the confined LO-phonon frequency shift [23]. This study showed that the experimental frequency shift of the first InAs-confined LO phonon was well reproduced by an ab initio calculation based on the density-functional theory.…”

“…In the case of InAs/GaAs QDs, monomodal or bimodal emission bands are generally observed unless a special growth technique is used [14]. In the case of InAs/InP QDs or QSs, multimodal emission spectra with up to eight distinguishable components are often observed [8,11,[15][16][17][18][19][20][21][22][23]. This multimodal emission is attributed to the presence of well-defined families of QDs or QSs corresponding to ultrathin islands with integer ML variation of InAs thickness between three and ten MLs.…”

Temperature dependence of the photoluminescence from InP/GaAs type-II ultrathin quantum wells

“…We note that the PL peak position shifts from 1.432 to 1.470 eV when the average QW thickness is decreased from 1.43 MLs to 0.95 MLs. Blue shift in the PL peak energy with the reduction in ultrathin QW thickness has been observed earlier for InAs/GaAs, InAs/InP, GaAs/GaAsSb and ZnSTe/ZnTe ultrathin QWs and it has been shown there that this is due to the quantum confinement effect in the QWs [2,[13][14][15]. We have also confirmed the type-II nature of these QWs by performing intensity-dependent PL measurements, where we observed that the PL peak energy increases linearly with the cube root of laser excitation power [16].…”