Towards InAs/InGaAs/GaAs Quantum Dot Solar Cells Directly Grown on Si Substrate

Azeza, B.; Alouane, Mohamed Helmi Hadj; Ilahi, Bouraoui; Patriarche, G.; Sfaxi, L.; Fouzri, A.; Maâref, H.; Mghaieth, Ridha

doi:10.3390/ma8074544

Cited by 11 publications

(6 citation statements)

References 31 publications

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“…However, it is noteworthy that an increase in photon energy above ε g leads to a slight decrease of the photoresponse. Naturally, this confirms that metamorphic QDs, despite being effective recombination centers [ 1 , 2 , 12 , 22 ], are more efficient contributors to photocurrent than MB [ 5 , 6 , 23 ].…”

Section: Resultsmentioning

confidence: 56%

“…Metamorphic InAs QD structures have found successful applications in the design and fabrication of IR photonic and light-sensitive devices, such as lasers [ 19 , 20 ], single-photon sources [ 3 , 7 , 21 , 22 ], and solar cells [ 23 – 25 ]. In(Ga)As QD photodetectors based on interband and intersubband transitions are currently actively investigated for enhanced detection from near-IR to longwave-IR ranges due to their response to the irradiation at normal incidence [ 26 – 30 ].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2018

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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.

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Section: Resultsmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

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

et al. 2018

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“…Owing to these peculiar properties, such nanostructures have found successful applications in the design and fabrication of infrared (IR) photonic and light-sensitive devices, such as QD lasers [28,29], single-photon emitters [30][31][32], and solar cells [33][34][35]. Very recently, we have shown that normal incident light at 1.3-1.55 μm is absorbed by metamorphic QD structures, based on photocurrent (PC) measurements [36].…”

Section: Introductionmentioning

confidence: 99%

Defect influence on in-plane photocurrent of InAs/InGaAs quantum dot array: long-term electron trapping and Coulomb screening

et al. 2019

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Metamorphic InAs/In 0.15 Ga 0.85 As and InAs/In 0.31 Ga 0.69 As quantum dot (QD) arrays are known to be photosensitive in the telecommunication ranges at 1.3 and 1.55 μm, respectively; however, for photonic applications of these nanostructures, the effect of levels related to defects still needs in-depth investigation. We have focused on the influence of electron traps of defects on photocurrent (PC) in the plane of the QD array, studying by PC and deep level thermally stimulated current spectroscopy together with HRTEM and theoretical modeling. In the structures, a rich spectrum of electron trap levels of point defects EL6 (E c − 0.37 eV), EL7 (0.29-0.30 eV), EL8 (0.27 eV), EL9/M2 (0.22-0.23 eV), EL10/M1 (0.16 eV), M0 (∼0.11 eV) and three extended defects ED1/EL3 (0.52-0.54), ED2/EL4 (0.47-0.48 eV), ED3/EL5 (0.42-0.43 eV) has been identified. Among them, new defect levels undiscovered earlier in InAs/InGaAs nanostructures has been detected, in particular, EL8 and M0. The found electron traps are shown to affect a time-dependent PC at low temperatures. Besides a long-term kinetics due to trap charging, a prolonged PC decrement versus time is measured under constant illumination. The decrement is interpreted to be related to a Coulomb screening of the conductivity channel by the electrons captured in the QD interface traps. The decrement is well fitted by allometric exponents, which means many types of traps involved in electron capturing. This study provides new findings into the mechanism of in-plane PC of QD arrays, showing a crucial importance of growth-related defects on photoresponsivity at low temperatures.

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“…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 ].…”

Section: Introductionmentioning

confidence: 99%

“…Photovoltage (PV) or photoconductivity (PC) studies is an ideal tool for the determination of the photoresponse as function of light energy, transitions between levels, carrier transport, and operating range of the device [ 10 , 43 , 44 ]. However, despite that some studies of the photoelectric properties of structures with metamorphic InAs QDs have been performed in last years [ 37 – 39 , 43 ], full aspects of the photoresponse mechanism still remain unclear, as along with the influence of the MB on the properties of the nanostructures. In particular, effects of the GaAs substrate and related interfaces on the photoelectric spectra of InAs/InGaAs/GaAs QD structures have not been explored in details.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2017

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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.

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Towards InAs/InGaAs/GaAs Quantum Dot Solar Cells Directly Grown on Si Substrate

Cited by 11 publications

References 31 publications

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

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

Defect influence on in-plane photocurrent of InAs/InGaAs quantum dot array: long-term electron trapping and Coulomb screening

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

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