Local photocurrent mapping of InAs/InGaAs/GaAs intermediate-band solar cells using scanning near-field optical microscopy

Rouis, W.; Haggui, Mohamed; Rekaya, S.; Sfaxi, L.; Mghaieth, Ridha; Maâref, H.; Fumagalli, P.

doi:10.1016/j.solmat.2015.09.026

Cited by 14 publications

(7 citation statements)

References 38 publications

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“…5 c. Furthermore, an essential advantage of such a substrate could manifest itself in solar cell design. A low-resistive substrate allows for utilization of the configuration with the “–” contact on the sample bottom [ 24 , 38 – 40 , 59 ], non-shadowing the MBE structure from the sunlight.…”

Section: Resultsmentioning

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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Section: Resultsmentioning

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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“…Considering mapping, the aim is to obtain as much information as possible using non-destructive techniques. For this reason, the optical or semi-optical methods such as: high-resolution X-ray diffraction (HR-XRD) [24], photoluminescence (PL) [22,24,25,30,31,33], local photocurrent mapping (LPM) [32,34], spatially separated pump-probe (SSPP) spectra [21], lock-in thermography [20], scanning thermal microscopy (STM) [28] are mostly preferred. In many cases, however, contactless electric [35] or non-destructive tactile methods such as atomic force microscopy (AFM) [23] are also used.…”

Section: Introductionmentioning

confidence: 99%

Multi-technique characterisation of InAs-on-GaAs wafers with circular defect pattern

2024

Opto-Electronics Review

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The article presents the results of diameter mapping for circular-symmetric disturbance of homogeneity of epitaxially grown InAs (100) layers on GaAs substrates. The set of acceptors (beryllium) doped InAs epilayers was studied in order to evaluate the impact of Be doping on the 2-inch InAs-on-GaAs wafers quality. During the initial identification of size and shape of the circular pattern, non-destructive optical techniques were used, showing a 100% difference in average roughness between the wafer centre and its outer part. On the other hand, no volumetric (bulk) differences are detectable using Raman spectroscopy and highresolution X-ray diffraction. The correlation between Be doping level and circular defect pattern surface area has been found.

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“…is method provides QDs with particular structural properties such as unstrained, uniform, not very dense, with high symmetry, and of different shapes with reference to conventional strained QDs. Due to these characteristics, the optical properties of unstrained QDs are interesting for various increasing high-performance applications in optoelectronic devices, namely, lasers and solar cells [3,4], in addition to quantum cryptography [5].…”

Section: Introductionmentioning

confidence: 99%

Theoretical Study of Excitonic Complexes in GaAs/AlGaAs Quantum Dots Grown by Filling of Nanoholes

Omri

Sayari

Sfaxi

2021

Advances in Condensed Matter Physics

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In this work, a theoretical study of the electronic and the optical properties of a new family of strain-free GaAs/AlGaAs quantum dots (QDs) obtained by AlGaAs nanohole filling is presented. The considered model consists of solving the three-dimensional effective-mass Schrödinger equation, thus providing a complete description of the neutral and charged complex excitons’ fine structure. The QD size effect on carrier confinement energies, wave functions, and s-p splitting is studied. The direct Coulomb interaction impact on the calculated s and p states’ transition energies is investigated. The behaviour of the binding energy of neutral and charged excitons (X− and X+) and biexciton XX versus QD height is studied. The addition of the correlation effect allows to explain the nature of biexcitons often observed experimentally.

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Local photocurrent mapping of InAs/InGaAs/GaAs intermediate-band solar cells using scanning near-field optical microscopy

Cited by 14 publications

References 38 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

Multi-technique characterisation of InAs-on-GaAs wafers with circular defect pattern

Theoretical Study of Excitonic Complexes in GaAs/AlGaAs Quantum Dots Grown by Filling of Nanoholes

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