Heavy Mediator at Quantum Dot/Graphene Heterojunction for Efficient Charge Carrier Transfer: Alternative Approach for High-Performance Optoelectronic Devices

AbstractAll-inorganic CsPbI3 perovskite quantum dots have received substantial research interest for photovoltaic applications because of higher efficiency compared to solar cells using other quantum dots materials and the various exciting properties that perovskites have to offer. These quantum dot devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. We demonstrate higher mechanical endurance of quantum dot films compared to bulk thin film and highlight the importance of further research on high-performance and flexible optoelectronic devices using nanoscale grains as an advantage. Specifically, we develop a hybrid interfacial architecture consisting of CsPbI3 quantum dot/PCBM heterojunction, enabling an energy cascade for efficient charge transfer and mechanical adhesion. The champion CsPbI3 quantum dot solar cell has an efficiency of 15.1% (stabilized power output of 14.61%), which is among the highest report to date. Building on this strategy, we further demonstrate a highest efficiency of 12.3% in flexible quantum dot photovoltaics.

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Deciphering the role of quantum dot size in the ultrafast charge carrier dynamics at the perovskite–quantum dot interface

Journal of Materials Chemistry C ◽

10.1039/d0tc03835k ◽

2020 ◽

Vol 8 (42) ◽

pp. 14834-14844

Author(s):

Piotr Piatkowski ◽

Sofia Masi ◽

Pavel Galar ◽

Mario Gutiérrez ◽

Thi Tuyen Ngo ◽

...

Keyword(s):

Quantum Dot ◽

Charge Carrier ◽

Rate Constants ◽

Transient Absorption ◽

Carrier Dynamics ◽

Carrier Transfer ◽

Charge Carrier Dynamics ◽

Conduction Bands

Charge-carrier transfer (CT) from the perovskite host to PbS QDs were studied using fs-transient absorption and THz techniques. The CT rate constants increase with the size of QDs due to a change in the position of valence and conduction bands in PbS QDs.

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Temperature-Dependent Charge Carrier Transfer in Colloidal Quantum Dot/Graphene Infrared Photodetectors

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c15226 ◽

2020 ◽

Author(s):

Matthias J. Grotevent ◽

Claudio U. Hail ◽

Sergii Yakunin ◽

Dominik Bachmann ◽

Gökhan Kara ◽

...

Keyword(s):

Quantum Dot ◽

Charge Carrier ◽

Infrared Photodetectors ◽

Temperature Dependent ◽

Carrier Transfer ◽

Colloidal Quantum Dot

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High-Performance Quantum Dot Optoelectronic Devices

Frontiers in Optics ◽

10.1364/fio.2006.fwg1 ◽

2006 ◽

Author(s):

P. Bhattacharya ◽

Z. Mi ◽

X-H. Su

Keyword(s):

Quantum Dot ◽

High Performance ◽

Optoelectronic Devices

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Temperature-Dependent Charge Carrier Transfer in Colloidal Quantum Dot/Graphene Infrared Photodetectors

10.26434/chemrxiv.12800030.v1 ◽

2020 ◽

Author(s):

Matthias Grotevent ◽

Claudio U. Hail ◽

Sergii Yakunin ◽

Dominik Bachmann ◽

Gökhan Kara ◽

...

Keyword(s):

Quantum Dot ◽

Charge Carrier ◽

Room Temperature ◽

Red Light ◽

Surface States ◽

Surface Oxidation ◽

Large Temperature ◽

Temperature Dependent ◽

Carrier Transfer ◽

Specific Detectivity

Colloidal PbS quantum dot (QD)/graphene hybrid photodetectors are emerging QD technologies for affordable infra-red light detectors. By interfacing the QDs with graphene, the photosignal of these detectors is amplified, leading to high responsivity values. While these detectors have been mainly operated at room temperature, low-temperature operation is required for extending their spectral sensitivity beyond a wavelength of 3 μm. Here, we unveil the temperature-dependent response of PbS QD/graphene photodetectors by performing steady-state and time-dependent measurements over a large temperature range of 80–300 K. We find that the temperature dependence of photo-induced charge carrier transfer from the QD layer to graphene is (i) not impeded by freeze-out of the (Schottky-like) potential barrier at low temperatures, (ii) tremendously sensitive to QD surface states (surface oxidation), and (iii) minimally affected by the ligand exposure time and QD layer thickness. Moreover, the specific detectivity of our detectors increases with cooling, with a maximum measured specific detectivity of at least 10<sup>10</sup> Jones at a wavelength of 1280 nm and temperature of 80 K, which is an order of magnitude larger compared to the corresponding room temperature value. The temperature- and gate-voltage-dependent characterization presented here constitute an important step in expanding our knowledge of charge transfer at interfaces of low dimensional materials and towards the realization of next-generation optoelectronic devices.<br>

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Balancing Charge Carrier Transport in a Quantum Dot P–N Junction toward Hysteresis-Free High-Performance Solar Cells

ACS Energy Letters ◽

10.1021/acsenergylett.8b00130 ◽

2018 ◽

Vol 3 (4) ◽

pp. 1036-1043 ◽

Cited By ~ 17

Author(s):

Yuljae Cho ◽

Bo Hou ◽

Jongchul Lim ◽

Sanghyo Lee ◽

Sangyeon Pak ◽

...

Keyword(s):

Solar Cells ◽

Quantum Dot ◽

Charge Carrier ◽

High Performance ◽

Carrier Transport ◽

Charge Carrier Transport

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Colloidal quantum dot ligand engineering for high performance solar cells

Energy & Environmental Science ◽

10.1039/c5ee03887a ◽

2016 ◽

Vol 9 (4) ◽

pp. 1130-1143 ◽

Cited By ~ 177

Author(s):

Ruili Wang ◽

Yuequn Shang ◽

Pongsakorn Kanjanaboos ◽

Wenjia Zhou ◽

Zhijun Ning ◽

...

Keyword(s):

Quantum Dots ◽

Solar Cells ◽

Quantum Dot ◽

High Performance ◽

Light Emitting Diodes ◽

Optoelectronic Devices ◽

Colloidal Quantum Dots ◽

Solution Processed ◽

Light Emitting ◽

Colloidal Quantum Dot

Colloidal quantum dots (CQDs) are fast-improving materials for next-generation solution-processed optoelectronic devices such as solar cells, photocatalysis, light emitting diodes, and photodetectors.

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Modelling charge transport and electro-optical characteristics of quantum dot light-emitting diodes

npj Computational Materials ◽

10.1038/s41524-021-00591-9 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Sung-Min Jung ◽

Tae Hoon Lee ◽

Sang Yun Bang ◽

Soo Deok Han ◽

Dong-Wook Shin ◽

...

Keyword(s):

Quantum Dot ◽

Charge Carrier ◽

Charge Transport ◽

High Performance ◽

Light Emitting Diodes ◽

Carrier Dynamics ◽

Computational Method ◽

Optical Characteristics ◽

Light Emitting ◽

Charge Carrier Dynamics

AbstractsQuantum dot light-emitting diodes (QD-LEDs) are considered as competitive candidate for next-generation displays or lightings. Recent advances in the synthesis of core/shell quantum dots (QDs) and tailoring procedures for achieving their high quantum yield have facilitated the emergence of high-performance QD-LEDs. Meanwhile, the charge-carrier dynamics in QD-LED devices, which constitutes the remaining core research area for further improvement of QD-LEDs, is, however, poorly understood yet. Here, we propose a charge transport model in which the charge-carrier dynamics in QD-LEDs are comprehensively described by computer simulations. The charge-carrier injection is modelled by the carrier-capturing process, while the effect of electric fields at their interfaces is considered. The simulated electro-optical characteristics of QD-LEDs, such as the luminance, current density and external quantum efficiency (EQE) curves with varying voltages, show excellent agreement with experiments. Therefore, our computational method proposed here provides a useful means for designing and optimising high-performance QD-LED devices.

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