Electrical and structural characterization of InAs/InGaAs quantum dot structures on GaAs

Rimada, Julio C.; Prezioso, M.; Nasi, L.; Gombia, E.; Mosca, R.; Trevisi, Giovanna; Seravalli, L.; Frigeri, P.; Bocchi, C.; Franchi, S.

doi:10.1016/j.mseb.2008.10.007

Cited by 14 publications

(36 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[ 43 ]. The buffer layer is filled by numerous shallow levels and band non-uniformities originated from MBE growth defects and doping centers that redshift the interband absorption of GaAs [ 33 , 46 , 54 , 55 ]. For the conventional buffer-contacted InAs/GaAs nanostructure, the onset at 1.05 eV of the PV spectrum in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…As a result, InAs/InGaAs QD structures have attracted much interest in last decade [ 27 – 29 ]. By growing the QDs on the InGaAs MB, one can observe essential differences in the formation process and QD optical properties compared with conventional ones in GaAs matrix [ 25 , 30 – 33 ]. For example, the InGaAs confining layer reduces the lattice mismatch between QDs and buffer and, hence, strains in QDs.…”

Section: Introductionmentioning

confidence: 99%

“…As well, there have been hopeful attempts to apply the photoelectric properties of the metamorphic InAs QD structures on the design of such light-sensitive devices as metamorphic infrared photodetectors [ 11 – 13 ] and solar cells [ 37 – 39 ]. Some studies were carried out to develop structure design [ 25 , 31 – 33 ] and other ones to improve photoelectric properties [ 39 , 40 ]. Investigations are going on to reduce the strains in the heterostructures [ 34 , 41 ], as this leads to a substantial improvement in the photocurrent density and spectral response of solar cells [ 39 , 40 ] as well as in the photoemission efficiency of such structures [ 29 , 32 , 42 ].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Bipolar Effects in Photovoltage of Metamorphic InAs/InGaAs/GaAs Quantum Dot Heterostructures: Characterization and Design Solutions for Light-Sensitive Devices

et al. 2017

View full text Add to dashboard Cite

The bipolar effect of GaAs substrate and nearby layers on photovoltage of vertical metamorphic InAs/InGaAs in comparison with pseudomorphic (conventional) InAs/GaAs quantum dot (QD) structures were studied. Both metamorphic and pseudomorphic structures were grown by molecular beam epitaxy, using bottom contacts at either the grown n +-buffers or the GaAs substrate. The features related to QDs, wetting layers, and buffers have been identified in the photoelectric spectra of both the buffer-contacted structures, whereas the spectra of substrate-contacted samples showed the additional onset attributed to EL2 defect centers. The substrate-contacted samples demonstrated bipolar photovoltage; this was suggested to take place as a result of the competition between components related to QDs and their cladding layers with the substrate-related defects and deepest grown layer. No direct substrate effects were found in the spectra of the buffer-contacted structures. However, a notable negative influence of the n +-GaAs buffer layer on the photovoltage and photoconductivity signal was observed in the InAs/InGaAs structure. Analyzing the obtained results and the performed calculations, we have been able to provide insights on the design of metamorphic QD structures, which can be useful for the development of novel efficient photonic devices.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bipolar Effects in Photovoltage of Metamorphic InAs/InGaAs/GaAs Quantum Dot Heterostructures: Characterization and Design Solutions for Light-Sensitive Devices

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Furthermore, metamorphic QDs have shown interesting properties such as (i) a high QD density [ 14 ], (ii) the possibility to widely tune QD and wetting layer (WL) levels [ 10 , 15 ], and (iii) good performances of active elements in light-emitting devices [ 16 ]. However, the recent investigations of deep levels in metamorphic QDs showed that, despite InAs/In 0.15 Ga 0.85 As QD structures having a total defect density close to the QD layer comparable to that of InGaAs/GaAs pseudomorphic QDs, metamorphic structures with higher x demonstrated higher defect densities [ 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Interband Photoconductivity of Metamorphic InAs/InGaAs Quantum Dots in the 1.3–1.55-μm Window

et al. 2018

View full text Add to dashboard Cite

Photoelectric properties of the metamorphic InAs/InxGa1 − xAs quantum dot (QD) nanostructures were studied at room temperature, employing photoconductivity (PC) and photoluminescence spectroscopies, electrical measurements, and theoretical modeling. Four samples with different stoichiometry of InxGa1 − xAs cladding layer have been grown: indium content x was 0.15, 0.24, 0.28, and 0.31. InAs/In0.15Ga0.85As QD structure was found to be photosensitive in the telecom range at 1.3 μm. As x increases, a redshift was observed for all the samples, the structure with x = 0.31 was found to be sensitive near 1.55 μm, i.e., at the third telecommunication window. Simultaneously, only a slight decrease in the QD PC was recorded for increasing x, thus confirming a good photoresponse comparable with the one of In0.15Ga0.75As structures and of GaAs-based QD nanostructures. Also, the PC reduction correlate with the similar reduction of photoluminescence intensity. By simulating theoretically the quantum energy system and carrier localization in QDs, we gained insight into the PC mechanism and were able to suggest reasons for the photocurrent reduction, by associating them with peculiar behavior of defects in such a type of structures. All this implies that metamorphic QDs with a high x are valid structures for optoelectronic infrared light-sensitive devices.

show abstract

“…Using capacitance-voltage (C-V) measurements of capped InAs QD layers, several groups have reported carrier depletion in the vicinity of the QD layers. [10][11][12] Since the carrier depletion occurs primarily for InAs coverage beyond 3 monolayers (ML), it is often attributed to strain relaxation-induced defects which act as carrier traps. 13,14 However, for C-V and scanning capacitance microscopy, n is spatially averaged over 100s of nm 2 and lm 2 , i.e., 10-100 000 QDs.…”

mentioning

confidence: 99%

Profiling the local carrier concentration across a semiconductor quantum dot

Walrath

Lin

Huang

et al. 2015

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

Electrical and structural characterization of InAs/InGaAs quantum dot structures on GaAs

Cited by 14 publications

References 11 publications

Bipolar Effects in Photovoltage of Metamorphic InAs/InGaAs/GaAs Quantum Dot Heterostructures: Characterization and Design Solutions for Light-Sensitive Devices

Bipolar Effects in Photovoltage of Metamorphic InAs/InGaAs/GaAs Quantum Dot Heterostructures: Characterization and Design Solutions for Light-Sensitive Devices

Interband Photoconductivity of Metamorphic InAs/InGaAs Quantum Dots in the 1.3–1.55-μm Window

Profiling the local carrier concentration across a semiconductor quantum dot

Contact Info

Product

Resources

About