Carrier transport properties in the vicinity of single self-assembled quantum dots determined by low-voltage cathodoluminescence imaging

Dupuy, Emmanuel; Morris, Denis; Pauc, N.; Aimez, Vincent; Gendry, M.; Drouin, Dominique

doi:10.1063/1.3072613

Cited by 10 publications

(7 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The temperature dependence of L can be attributed to the drop in mobility caused by phonon scattering. For phonon scattering, the mobility in different InAs structures must have a universal value, varying in the interval 100-400 cm 2 /V s. 15 This allows us to estimate the hole lifetime having the order of 4 Â 10 À10 s in our samples and 5 Â 10 À11 s in Dupuy et al 14 Authors C.Y.C., A.S., and H.E.R. gratefully acknowledge support for this work from NSERC, CIPI, CSA, and OCE.…”

Section: Drift Term Is Absent and The Solution Is Pðxþmentioning

confidence: 99%

Electron beam induced current in InSb-InAs nanowire type-III heterostructures

et al. 2012

View full text Add to dashboard Cite

Thermally driven unipolar and bipolar spin diode based on double quantum dots J. Appl. Phys. 112, 084324 (2012) Temperature-dependent properties of semimetal graphite-ZnO Schottky diodes Appl. Phys. Lett. 101, 162106 (2012) Millimeterwave Schottky diode on grapene monolayer via asymmetric metal contacts J. Appl. Phys. 112, 084302 (2012) Electrical and microstructural analyses of 200MeV Ag14+ ion irradiated Ni/GaN Schottky barrier diode Appl. Phys. Lett. 101, 153508 (2012) Theory of the suspended graphene varactor

show abstract

Section: Drift Term Is Absent and The Solution Is Pðxþmentioning

confidence: 99%

Electron beam induced current in InSb-InAs nanowire type-III heterostructures

et al. 2012

View full text Add to dashboard Cite

show abstract

“…In this contribution, we present measurements of excess carrier diffusion lengths before capture by single self-assembled quantum dots (QDs) [3]. Measurements were performed on InAs/InP QDs emitting around 1.55 µm by low-voltage cathodoluminescence in a SEM (Fig.1a).…”

Section: Investigation Of Single Nanostructures Requires a Technique mentioning

confidence: 99%

“…Therefore, the diffusion length of the excited species (carriers, excitons) can be directly measured. This approach has been successfully applied to map high density threading dislocations in GaN epilayer and extract the diffusion length from CL profile measured across a single dislocation core [2].In this contribution, we present measurements of excess carrier diffusion lengths before capture by single self-assembled quantum dots (QDs) [3]. Measurements were performed on InAs/InP QDs emitting around 1.55 µm by low-voltage cathodoluminescence in a SEM (Fig.1a).…”

mentioning

confidence: 98%

Low-Voltage Cathodoluminescence as a High Spatial Resolution Technique for Nanostructure Characterization

Dupuy¹,

Pauc²,

Morris³

et al. 2010

Microsc Microanal

View full text Add to dashboard Cite

Scanning cathodoluminescence (CL) microscopy and spectroscopy is a very powerful microanalysis technique for studying the optical and structural properties of bulk and low-dimensional semiconductor materials [1]. Growing interests for this technique are driven by its relatively high spatial resolution, its contactless character, and its ease of use without any special sample preparation. Moreover, this technique is generally non-destructive and can be combined with the normal imaging capabilities and analysis possibilities of the scanning electron microscope (SEM).Investigation of single nanostructures requires a technique capable of sub-micron spatial resolution. Spatial resolution achievable in CL mode is a function of three parameters, which are the diameter of the exciting electron beam, the primary electrons scattering radius and the diffusion length of generated carriers. Combining a recent field emission electron source that provides a small and stable focused beam and a low-voltage acceleration source for the primary electrons, the interaction volume into which electron-hole pairs are created is reduced toward a quasi-point source. Under these conditions, the spatial resolution in CL is essentially limited by the diffusion length in the material. Therefore, the diffusion length of the excited species (carriers, excitons) can be directly measured. This approach has been successfully applied to map high density threading dislocations in GaN epilayer and extract the diffusion length from CL profile measured across a single dislocation core [2].In this contribution, we present measurements of excess carrier diffusion lengths before capture by single self-assembled quantum dots (QDs) [3]. Measurements were performed on InAs/InP QDs emitting around 1.55 µm by low-voltage cathodoluminescence in a SEM (Fig.1a). These semiconductor nanostructures are promising active materials for the realization of nanophotonic devices operating at telecom wavelengths, such as single-photon sources for quantum cryptography systems or entangled photon emitters for quantum computing. Investigating carrier transport in the vicinity of single QDs is thus relevant to optimize device performances.Cathodoluminescence characterization was conducted using a Zeiss Supra 55 VP field emission gun SEM equipped with a cryogenic stage (5 K to room temperature) coupled to a Gatan MonoCL 2 setup with a cooled InGaAs photomultiplier tube. At low voltage (1 kV), the SEM electron spot size is as small as about 3 nm and excess carriers are generated in sub-10-nm volume in InP providing a quasi-point source [4]. At 1 kV, we have spatially resolved individual QDs, which appear as correlated bright spots on CL micrographs (Fig.1c). A simple diffusion model adapted to our quantum heterostructure has been developed to extract the diffusion length. Fig.1b presents a schematic of the experiment. Excess carriers generated in sub-10-nm volume of the barrier are 820

show abstract

“…For sample A, the E a value fitted agrees well with the energy difference between the ground state of hole and InGaAs valence band edge. But since carrier diffusion lengths in III-V semiconductor ͑10-100 s of nanometer͒ 15,16 are more than the thickness of InGaAs insertion layer, InP CBLs in sample C, D, and E can still effectively suppress the thermal escape of carriers in InAsSb nanostructures and leads to the PL signal still being observed at 330 K. For sample B, though the E a value fitted ͑131 meV͒ is not as high as the energy barriers introduced by InP CBLs for electrons and holes, it is still much larger than that of sample A.…”

mentioning

confidence: 99%