Towards controlled synthesis and better understanding of highly luminescent PbS/CdS core/shell quantum dots

Zhao, Haiguang; Chaker, Mohamed; Wu, Nianqiang; Ma, Dongling

doi:10.1039/c1jm11205h

Cited by 123 publications

(258 citation statements)

References 27 publications

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“…As previously reported, the shell of PbS@CdS QDs is mainly composed of CdS. 20,21 The average overall diameter of the pure PbS QDs or the core@shell QDs was estimated from TEM images. As-synthesized PbS and core@shell QDs exhibit a very well dened rst-exciton absorption peak and PL peak.…”

Section: Synthesis and Structure Of Pbs@cds Core@shell Qdsmentioning

confidence: 89%

“…The pure PbS and core@shell PbS@CdS QDs range from 3 nm to 6 nm with a typical QY of 19-85% in toluene, a <9% size distribution and a lifetime of 1-3 ms, indicating that our synthesis yields good quality QDs, consistent with the PbS QDs reported in the literature. 20,21 In fact, even with very thin shell, around 0.1-0.3 nm, the QY and stability of plain PbS QDs can be largely enhanced. 20,24 The electron transfer behavior of PbS@CdS QDs was investigated by loading QDs on mesoporous thin lms prepared by standard tape casting oxide paste onto transparent glass substrates.…”

Section: Synthesis and Structure Of Pbs@cds Core@shell Qdsmentioning

confidence: 99%

“…20,21 In fact, even with very thin shell, around 0.1-0.3 nm, the QY and stability of plain PbS QDs can be largely enhanced. 20,24 The electron transfer behavior of PbS@CdS QDs was investigated by loading QDs on mesoporous thin lms prepared by standard tape casting oxide paste onto transparent glass substrates. The lms were composed of wide bandgap nanoparticles (TiO 2 and SnO 2 were used) attached to the QDs via MAA linker, the thiol groups binding to the QDs surface and the carboxylic groups binding to the oxide surface.…”

Section: Synthesis and Structure Of Pbs@cds Core@shell Qdsmentioning

confidence: 99%

“…20 Pure PbS QDs with size in the range 3.0 to 5.2 nm were considered as a benchmark, to evaluate the effect of the shell on the charge injection rate. In core@shell systems we expect the shell to act as a barrier to be overcome through tunneling for the injection to take place.…”

Section: Electron Transfer: the Effect Of Oxidementioning

confidence: 99%

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Controlling photoinduced electron transfer from PbS@CdS core@shell quantum dots to metal oxide nanostructured thin films

et al. 2014

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N-type metal oxide solar cells sensitized by infrared absorbing PbS quantum dots (QDs) represent a promising alternative to traditional photovoltaic devices. However, colloidal PbS QDs capped with pure organic ligand shells suffer from surface oxidation that affects the long term stability of the cells.Application of a passivating CdS shell guarantees the increased long term stability of PbS QDs, but can negatively affect photoinduced charge transfer from the QD to the oxide and the resulting photoconversion efficiency (PCE). For this reason, the characterization of electron injection rates in these systems is very important, yet has never been reported. Here we investigate the photoelectron transfer rate from PbS@CdS core@shell QDs to wide bandgap semiconducting mesoporous films using photoluminescence (PL) lifetime spectroscopy. The different electron affinity of the oxides (SiO 2 , TiO 2 and SnO 2 ), the core size and the shell thickness allow us to fine tune the electron injection rate by determining the width and height of the energy barrier for tunneling from the core to the oxide.

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Section: Synthesis and Structure Of Pbs@cds Core@shell Qdsmentioning

confidence: 89%

Section: Synthesis and Structure Of Pbs@cds Core@shell Qdsmentioning

confidence: 99%

Section: Synthesis and Structure Of Pbs@cds Core@shell Qdsmentioning

confidence: 99%

Section: Electron Transfer: the Effect Of Oxidementioning

confidence: 99%

See 2 more Smart Citations

Controlling photoinduced electron transfer from PbS@CdS core@shell quantum dots to metal oxide nanostructured thin films

et al. 2014

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“…Compared with the control devices made with P3HT and PCBM mixtures, the power conversion efficiency of the hybrid cells increased by approximately 18 %, due to the enhanced absorption and transportation of photoexcited charges related to the QDs and MWCNTs, respectively. Considering the stability issue of plain PbS QDs and significantly improved photo-and thermal-stability of the PbS/CdS core-shell QDs, [66,[89][90][91] it is interesting to explore the use of these coreshell QDs in solar cells. One negative factor, however, could be the inefficient charge transfer in these seemingly type-I QDs, where, unlike in type-II QDs, the shell may serve as a barrier for charge transfer.…”

Section: Hybrid Polymer-qd Solar Cellsmentioning

confidence: 99%

Semiconductor and Metallic Core–Shell Nanostructures: Synthesis and Applications in Solar Cells and Catalysis

Kim

Chen

et al. 2014

Chemistry A European J

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Nano-heterostructures have attracted great attention due to their extraordinary properties beyond those of their single-component counterparts. This review focuses on a specific type of hybrid structures: core-shell structures. In particular, we present and discuss the recent wet-chemical synthesis approaches for semiconductor and metallic core-shell nanostructures, and their relevant properties and potential applications in photovoltaics and catalysis, respectively.

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Highly Stable Colloidal “Giant” Quantum Dots Sensitized Solar Cells

Selopal

Zhao

Tong

et al. 2017

Adv Funct Materials

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Colloidal quantum dots (QDs) are widely studied due to their promising optoelectronic properties. This study explores the application of specially designed and synthesized “giant” core/shell CdSe/(CdS)x QDs with variable CdS shell thickness, while keeping the core size at 1.65 nm, as a highly efficient and stable light harvester for QD sensitized solar cells (QDSCs). The comparative study demonstrates that the photovoltaic performance of QDSCs can be significantly enhanced by optimizing the CdS shell thickness. The highest photoconversion efficiency (PCE) of 3.01% is obtained at optimum CdS shell thickness ≈1.96 nm. To further improve the PCE and fully highlight the effect of core/shell QDs interface engineering, a CdSexS1−x interfacial alloyed layer is introduced between CdSe core and CdS shell. The resulting alloyed CdSe/(CdSexS1−x)5/(CdS)1 core/shell QD‐based QDSCs yield a maximum PCE of 6.86%, thanks to favorable stepwise electronic band alignment and improved electron transfer rate with the incorporation of CdSexS1−x interfacial layer with respect to CdSe/(CdS)6 core/shell. In addition, QDSCs based on “giant” core/CdS‐shell or alloyed core/shell QDs exhibit excellent long‐term stability with respect to bare CdSe‐based QDSCs. The giant core/shell QDs interface engineering methodology offers a new path to improve PCE and the long‐term stability of liquid junction QDSCs.

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Towards controlled synthesis and better understanding of highly luminescent PbS/CdS core/shell quantum dots

Cited by 123 publications

References 27 publications

Controlling photoinduced electron transfer from PbS@CdS core@shell quantum dots to metal oxide nanostructured thin films

Controlling photoinduced electron transfer from PbS@CdS core@shell quantum dots to metal oxide nanostructured thin films

Semiconductor and Metallic Core–Shell Nanostructures: Synthesis and Applications in Solar Cells and Catalysis

Highly Stable Colloidal “Giant” Quantum Dots Sensitized Solar Cells

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