Fabrication and characterization of InAs/InGaAs sub-monolayer quantum dot solar cell with dot-in-a-well structure

Han, Im Sik; Kim, Jong Su; Kim, Jun Oh; Noh, Sam Kyu; Lee, Sang Jun

doi:10.1016/j.cap.2016.02.009

Cited by 25 publications

(14 citation statements)

References 24 publications

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“…Yet, a more optimal design of the vertical structures seems to be in use of a monotonous gradient of doping, including an n + -doped GaAs substrate as it is proposed in Refs [ 14 , 39 , 40 ]. This design is the most efficient and at the same time simplest.…”

Section: Resultsmentioning

confidence: 99%

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%

“…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%

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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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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

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“…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%

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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Change in Topography of InAs Submonolayer Nanostructures at the 2D to 3D Transition

Roca

Kamiya

2020

Physica Status Solidi (b)

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A strong topographical evidence of the 2D to 3D transition in InAs/GaAs nanostructures assembled by the submonolayer (SML) growth mode using molecular beam epitaxy (MBE) is reported. Whereas the 2D to 3D transition in InAs nanostructures assembled by the Stranski–Krastanov (SK) growth mode is well established with a critical thickness of around 1.7 monolayer (ML), the analogous phenomenon in SML‐grown nanostructures is not yet well understood. Herein, atomic force microscopy (AFM) is utilized to investigate the topographical changes associated with the 2D to 3D transition in SML nanostructures, and it is unambiguously shown that for a given number of stacks and GaAs matrix (spacer) layer thickness, there exists a critical thickness in the amount of deposited InAs per cycle, beyond which the nucleation of 3D nanostructures abruptly begins. It is also shown that the critical thickness decreases with increasing number of stacks as well as with decreasing GaAs matrix layer thickness. Moreover, the present work shows that InAs/GaAs SML nanostructures exist in two distinct forms: 2D wetting layer (WL)‐like islands and 3D quantum dot (QD)‐like structures.

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Fabrication and characterization of InAs/InGaAs sub-monolayer quantum dot solar cell with dot-in-a-well structure

Cited by 25 publications

References 24 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

Change in Topography of InAs Submonolayer Nanostructures at the 2D to 3D Transition

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