AlAs coating for stacked structure of self-assembled InAs/GaAs quantum dots

Yokota, Hiroki; Iizuka, Kanji; Okamoto, Hiroshi; Suzuki, Tohru

doi:10.1016/j.jcrysgro.2006.11.326

Cited by 5 publications

(2 citation statements)

References 9 publications

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“…The response peak of QD layer from sample A is at longer wavelength comparing to the response peak of sample B. This is consistent with the studies of Suzuki et al [ 14 ]. The intermixing of InAs with GaAs can be suppressed by inserting a thin AlAs layer between InAs and GaAs.…”

Section: Resultssupporting

confidence: 91%

Improvement of performance of InAs quantum dot solar cell by inserting thin AlAs layers

McPheeters

et al. 2011

Nanoscale Res Lett

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A new measure to enhance the performance of InAs quantum dot solar cell is proposed and measured. One monolayer AlAs is deposited on top of InAs quantum dots (QDs) in multistack solar cells. The devices were fabricated by molecular beam epitaxy. In situ annealing was intended to tune the QD density. A set of four samples were compared: InAs QDs without in situ annealing with and without AlAs cap layer and InAs QDs in situ annealed with and without AlAs cap layer. Atomic force microscopy measurements show that when in situ annealing of QDs without AlAs capping layers is investigated, holes and dashes are present on the device surface, while capping with one monolayer AlAs improves the device surface. On unannealed samples, capping the QDs with one monolayer of AlAs improves the spectral response, the open-circuit voltage and the fill factor. On annealed samples, capping has little effect on the spectral response but reduces the short-circuit current, while increasing the open-circuit voltage, the fill factor and power conversion efficiency.

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Section: Resultssupporting

confidence: 91%

Improvement of performance of InAs quantum dot solar cell by inserting thin AlAs layers

McPheeters

et al. 2011

Nanoscale Res Lett

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“…negative charging of dots suppresses photoelectron capture and increases the lifetimes of photogenerated electron-hole pairs. Another possibility to suppress thermal coupling between the quantized energy levels of QDs and the conduction band of GaAs is based on formation of a potential barrier around InAs QD by covering it with a AlAs layer that results in carrier confinement potential [20,21]. In such system, the impact of the WL-assisted capture to QDs at room temperatures is reduced due to the relative phase volume of InGaAs WLs reduction, since the In atoms in the WL are substituted by Al atoms [22].…”

Section: Introductionmentioning

confidence: 99%

Carrier dynamics and recombination in silicon doped InAs/GaAs quantum dot solar cells with AlAs cap layers

Кондратенко

Kozak

Rozouvan

et al. 2020

Semicond. Sci. Technol.

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The effects of doping InAs quantum dots (QDs) with Si on charge carrier dynamics and recombination in the InAs/GaAs quantum dot solar cells with AlAs cap layers was investigated. Non-radiative and radiative recombination paths in the doped cells were identified by changes in emission intensity, longwavelength photovoltage (PV) as well as time-resolved PV and photoluminescence (PL) measurements.We find that the reduction of long-wavelength PV and PL with n-doping is due to the electron population of the QD ground states and shrinkage of the depletion layer. The time constants, derived from the timeresolved PV, grow non-monotonically with increasing of the doping density in the QDs due to redistribution of electrostatic potential in the intrinsic region of p-i-n diode and electron population of EL2 defect states of GaAs barriers. We also find that the ground state emission from the InAs QDs decreases with n-doping. The results show that PL traces depends on carrier dynamic in the top QD layers populated partially with electrons from ionized impurities, whereas PV transients were found to be strongly dependent on recombination via QD and defect states located outside the depletion layer. We conclude that the non-radiative recombination of photogenerated electrons and holes via defects is suppressed due to the spatial separation by the local electric fields in and around doped AlAs/InAs QDs, as the potential profile of the intrinsic region is modulated spatially by built-in charges. The interpretation of experimental data suggests limiting mechanisms in the InAs/GaAs quantum dot solar cells operation and sheds light on possible approaches for their further improvement.

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Effects of Sb-soak on InAs quantum dots grown on (001) and (113)B GaAs substrates

Kumagai

Minami

et al. 2017

Journal of Crystal Growth

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AlAs coating for stacked structure of self-assembled InAs/GaAs quantum dots

Cited by 5 publications

References 9 publications

Improvement of performance of InAs quantum dot solar cell by inserting thin AlAs layers

Improvement of performance of InAs quantum dot solar cell by inserting thin AlAs layers

Carrier dynamics and recombination in silicon doped InAs/GaAs quantum dot solar cells with AlAs cap layers

Effects of Sb-soak on InAs quantum dots grown on (001) and (113)B GaAs substrates

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