Investigation of carrier escape mechanism in InAs/GaAs quantum dot solar cells

Dai, Yushuai; Bailey, Christopher G.; Kerestes, Christopher; Forbes, David V.; Hubbard, Seth M.

doi:10.1109/pvsc.2012.6317564

Cited by 12 publications

(5 citation statements)

References 20 publications

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“…The photocurrent in the reverse bias regime originates from some or all of the three processes mentioned earlier (figure 1). Excluding the dark current, the current under laser illumination is given by [13]…”

Section: Resultsmentioning

confidence: 99%

Carrier extraction behaviour in type II GaSb/GaAs quantum ring solar cells

Fujita

James

Carrington

et al. 2014

Semicond. Sci. Technol.

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The introduction of quantum dot (QD) or quantum ring (QR) nanostructures into GaAs single-junction solar cells has shown enhanced photo-response above the GaAs absorption edge, because of sub-bandgap photon absorption. However, to further improve solar cell performance a better understanding of the mechanisms of photogenerated carrier extraction from QDs and QRs is needed. In this work we have used a direct excitation technique to study type II GaSb/GaAs quantum ring solar cells using a 1064 nm infrared laser, which enables us to excite electron-hole pairs directly within the GaSb QRs without exciting the GaAs host material. Temperature and laser intensity dependence of the current-voltage characteristics revealed that the thermionic emission process produced the dominant contribution to the photocurrent and accounts for 98.9% of total photocurrent at 0 V and 300 K. Although the tunnelling process gives only a low contribution to the photocurrent, an enhancement of the tunnelling current was clearly observed when an external electric field was applied.

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Section: Resultsmentioning

confidence: 99%

Carrier extraction behaviour in type II GaSb/GaAs quantum ring solar cells

Fujita

James

Carrington

et al. 2014

Semicond. Sci. Technol.

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“…The escape of holes, because of their shallow confinement, is essentially thermally-driven, whereas a more complex picture may underlie the electrons escape. In fact, thermal escape is usually dominant for the escape from GS, whereas tunnelling can be significant for the higher energy states under high electric fields, on the order at least of a few tens of kV/cm as reported, for example, in [9,16]. Clearly, the relative strength of thermal-assisted or tunnelling-assisted mechanisms on the escape rate is very dependent on the QD energy levels and device structure as well.…”

Section: Model Overviewmentioning

confidence: 95%

Impact of carrier dynamics on the photovoltaic performance of quantum dot solar cells

Gioannini¹,

Cédola

Cappelluti³

2015

IET Optoelectronics

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The paper presents a theoretical investigation of the impact of individual electron and hole dynamics on the photovoltaic characteristics of InAs/GaAs quantum dot solar cells. The analysis is carried out by exploiting a model which includes a detailed description of QD kinetics within a drift-diffusion formalism. Steady-state and transient simulations show that hole thermal spreading across the closely spaced QD valence band states allows to extract the maximum achievable photocurrent from the QDs; on the other hand, slow hole dynamics turns QDs into efficient traps, impairing the short circuit current despite the extended light harvesting provided by the QDs.

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“…[56][57][58][59][60] Doping QD in the intrinsic region will affect the band profile and, therefore, the electric field in the intrinsic region. Accordingly, the change in electric field will also affect carrier dynamics as well as the solar cell device performance.…”

Section: Doping Effect On Inas/gaas Quantum Dot Solar Cell Performancementioning

confidence: 99%

Recent progress on quantum dot solar cells: a review

2016

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Abstract. Semiconductor quantum dots (QDs) have a potential to increase the power conversion efficiency in photovoltaic operation because of the enhancement of photoexcitation. Recent advances in self-assembled QD solar cells (QDSCs) and colloidal QDSCs are reviewed, with a focus on understanding carrier dynamics. For intermediate-band solar cells using selfassembled QDs, suppression of a reduction of open circuit voltage presents challenges for further efficiency improvement. This reduction mechanism is discussed based on recent reports. In QD sensitized cells and QD heterojunction cells using colloidal QDs well-controlled heterointerface and surface passivation are key issues for enhancement of photovoltaic performances. The improved performances of colloidal QDSCs are presented. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Investigation of carrier escape mechanism in InAs/GaAs quantum dot solar cells

Cited by 12 publications

References 20 publications

Carrier extraction behaviour in type II GaSb/GaAs quantum ring solar cells

Carrier extraction behaviour in type II GaSb/GaAs quantum ring solar cells

Impact of carrier dynamics on the photovoltaic performance of quantum dot solar cells

Recent progress on quantum dot solar cells: a review

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