Crystal Phase Quantum Dots

Akopian, N.; Patriarche, G.; Liu, L.; Harmand, J. C.; Zwiller, Val

doi:10.1021/nl903534n

Cited by 249 publications

(292 citation statements)

References 26 publications

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“…Controlled axial changes between the two crystal structures can be achieved by appropriate control over growth conditions [2]. The two phases differ in bandgap by ∼ 55 meV for InAs [4], enabling the production of devices, e.g., quantum dots via a 'phase heterostructuring' approach [5] rather than by compositional heterostructuring.…”

Section: Introductionmentioning

confidence: 99%

The influence of atmosphere on the performance of pure-phase WZ and ZB InAs nanowire transistors

et al. 2017

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Abstract. We compare the characteristics of phase-pure MOCVD grown ZB and WZ InAs nanowire transistors in several atmospheres: air, dry pure N 2 and O 2 , and N 2 bubbled through liquid H 2 O and alcohols to identify whether phase-related structural/surface differences affect their response. Both WZ and ZB give poor gate characteristics in dry state. Adsorption of polar species reduces off-current by 2 − 3 orders of magnitude, increases on-off ratio and significantly reduces sub-threshold slope. The key difference is the greater sensitivity of WZ to low adsorbate level. We attribute this to facet structure and its influence on the separation between conduction electrons and surface adsorption sites. We highlight the important role adsorbed species play in nanowire device characterisation. WZ is commonly thought superior to ZB in InAs nanowire transistors. We show this is an artefact of the moderate humidity found in ambient laboratory conditions: WZ and ZB perform equally poorly in the dry gas limit yet equally well in the wet gas limit. We also highlight the vital role density-lowering disorder has in improving gate characteristics, be it stacking faults in mixed-phase WZ or surface adsorbates in pure-phase nanowires.

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Section: Introductionmentioning

confidence: 99%

The influence of atmosphere on the performance of pure-phase WZ and ZB InAs nanowire transistors

et al. 2017

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“…Another interesting type of axial heterostructures uses alternating few nm short segments of the same chemical material but different crystal structure as e.g. in wurtzite/zincblende InP [18][19][20] and GaAs 21 NWs revealing a type-II band alignment.…”

Section: Introductionmentioning

confidence: 99%

Population dynamics and dephasing of excitons and electron-hole pairs in polytype wurtzite/zinc-blende InP nanowires

et al. 2017

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“…Unlike the bulk counterparts, the structure of the NWs can consist of pure phases of zinc-blende or wurtzite, or a mixture of the two phases. [5][6][7][8][9][10][11][12] Three different aspects of the wurtzite crystal structure in materials that in bulk exist only in zinc-blende form have been studied up to date. First, nucleation theories have been developed to investigate the appearance of wurtzite structure as a direction for obtaining pure crystal phases.…”

Section: Introductionmentioning

confidence: 99%

“…[13][14][15][16] Second, the calculations of the energy parameters of the band structure of wurtzite GaAs and InP [17][18][19][20] have attracted a significant interest. Finally, the energy structure of the zinc-blende wurtzite heterojunction 8,9 and the piece-wise wurtzite phase material in the NWs 10,21,22 have been studied experimentally using photoluminescence (PL) spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Valence band structure of polytypic zinc-blende/wurtzite GaAs nanowires probed by polarization-dependent photoluminescence

et al. 2012

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We conducted temperature-dependent measurements of the photoluminescence (PL) polarization on GaAs nanowires (NWs) with polytypic zinc-blende/wurtzite structure in order to probe the symmetry and energy structure of the valence band in the wurtzite segments of the NWs. The low-temperature measurements revealed that in most of the investigated cases, the ground level of the interface excitons responsible for the PL is formed by the heavy hole. To describe the observed temperature dependence of the degree of PL polarization, we developed a theoretical model that allows an estimation of the splitting between the heavy hole and light hole exciton subbands in these NWs. This splitting is smaller than expected in pure wurtzite on the basis of recent first-principles calculations, which may be attributed to the multiple twinned nature of the wurtzite sections, which effectively behave as a polytype of lower hexagonality.

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Crystal Phase Quantum Dots

Cited by 249 publications

References 26 publications

The influence of atmosphere on the performance of pure-phase WZ and ZB InAs nanowire transistors

The influence of atmosphere on the performance of pure-phase WZ and ZB InAs nanowire transistors

Population dynamics and dephasing of excitons and electron-hole pairs in polytype wurtzite/zinc-blende InP nanowires

Valence band structure of polytypic zinc-blende/wurtzite GaAs nanowires probed by polarization-dependent photoluminescence

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