| 1. |
- Liu, Cheng, et al.
(författare)
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Tuning the composition of heavy metal-free quaternary quantum dots for improved photoelectrochemical performance
- 2021
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 9:9, s. 5825-5832
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Tidskriftsartikel (refereegranskat)abstract
- Colloidal quantum dots (QDs) are promising building blocks towards the development of cost-effective and high-efficiency photoelectrochemical (PEC) cells. Unfortunately, the frequent use of QDs possessing heavy metals (e.g. Cd and Pb) in state-of-the-art QD-based PEC technologies is a major obstacle regarding their future commercial perspective. In this work, we synthesized heavy metal-free quaternary CuZnInS3 (CZIS) with variable Cu : Zn ratios and fabricated corresponding QDs-PEC devices via a facile chemical bath deposition (CBD) technique. It is revealed that the tuned CZIS (1Zn) QDs (i.e. Cu : Zn ratio of 1 : 1) can result in optimized optical properties including enhanced quantum yield, suppressed nonradiative recombination and extended excitonic lifetime. Accordingly, as-fabricated CZIS (1Zn) QD-based photoanodes demonstrated increased charge transfer rate and decreased electron transport resistance for improved PEC performance. The results indicate that tuning the composition of heavy metal-free multinary QDs is one of the promising pathways to achieve eco-friendly and high-performance PEC systems for solar hydrogen production.
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| 2. |
- Tong, Xin, et al.
(författare)
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Boosting the performance of eco-friendly quantum dots-based photoelectrochemical cells via effective surface passivation
- 2020
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 76
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Tidskriftsartikel (refereegranskat)abstract
- Photoelectrochemical (PEC) cells fabricated using environment-friendly colloidal quantum dots (QDs) are promising optoelectronic devices for future practical solar-to-hydrogen conversion. However, the majority of current eco-friendly QDs-based PEC cells exhibited low efficiency mainly due to the charge trapping at QDs’ surface states and interfacial recombination processes in devices. Here, eco-friendly AgInS2 (AIS) QDs-based PEC cells passivated with variable ZnS layers were fabricated and the effects of ZnS surface passivation on corresponding device performance were investigated. It is demonstrated that optimizing the thickness of the ZnS passivation layers can largely suppress the charge trapping/recombination and enhance the electron injection efficiency in the PEC devices, leading to a saturated photocurrent density of ∼5.7 mA/cm2 under standard AM 1.5 G solar illumination. Increasing the thickness of ZnS passivation layers can further inhibit the photocorrosion and give rise to higher device stability. These results indicate that ZnS surface passivation is a facile and efficient technique to boost the performance of eco-friendly QDs-based PEC cells.
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| 3. |
- Xia, Li, et al.
(författare)
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Synergistic tailoring of band structure and charge carrier extraction in "€œgreen"€ core/shell quantum dots for highly efficient solar energy conversion
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 442:2
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Tidskriftsartikel (refereegranskat)abstract
- Environment-friendly colloidal core/shell quantum dots (QDs) with controllable optoelectronic characteristics are promising building blocks for future commercial solar technologies. Herein, we synergistically tailor the electronic band structure and charge carrier extraction of eco-friendly AgInS2 (AIS)/ZnS core/shell QDs via Mn-alloying and Cu-doping in the core and shell, respectively. It is demonstrated that the Mn-alloying in AIS core can broaden the band gap to facilitate delocalization of photogenerated electrons into the shell and further incorporation of Cu in the ZnS shell enables the creation of Cu-related states that capture the photogenerated holes from core, thus leading to charge carrier recombination and accelerated transfer of photogenerated electrons in the core/shell QDs. As-prepared Mn-AIS/ZnS@Cu QDs were assembled as light harvesters in a photoelectrochemical (PEC) device for light-driven hydrogen evolution, delivering a maximum photocurrent density of ∼6.4 mA cm-2 with superior device stability under standard one sun irradiation (AM 1.5G, 100 mW cm-2). Our findings highlight that simultaneously engineering the band alignment and charge carrier dynamics of “green†core/shell QDs endow the feasibility to design future high-efficiency and durable solar hydrogen production systems.
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