Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 91
Filter
Add more filters










Publication year range
1.
Angew Chem Int Ed Engl ; : e202406167, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38818573

ABSTRACT

The planar triple-layer hole transport layer (HTL)-free carbon-based perovskite solar cells (C-PSCs) have outstanding advantages of low cost and high stability, but are limited by low efficiency. The formation of a 3D/2D heterojunction has been widely proven to enhance device performance. However, the 2D perovskite possesses multiple critical properties associated with 3D perovskite, including defect passivation, energy level, and charge transport properties, all of which can impact device performance. It is challenging to find a powerful means to achieve comprehensive regulation and trade-off of these key properties. Herein, we propose a chain-length engineering of alkylammonium spacer cations to achieve this goal. The results show that the 2D perovskite formed by short-chain alkylammonium cations primarily acts to passivate defects. With the increase in cation chain length, the 2D perovskite achieves a more matched energy level with 3D perovskite, enhancing the built-in electric field and promoting charge separation. However, the further increase in chain length impedes the charge transport due to the insulativity of organic cations. Comprehensively, the 2D perovskite formed by tetradecylammonium cations achieves the optimal balance of defect passivation, interface charge separation, and charge transport. The planar HTL-free C-PSCs exhibit a new record efficiency of 20.40% (certified 20.1%).

2.
Bioengineering (Basel) ; 11(5)2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38790293

ABSTRACT

Atopic dermatitis (AD), a prevalent chronic inflammatory skin disorder, is marked by impaired skin barrier function and persistent pruritus. It significantly deteriorates patients' quality of life, making it one of the most burdensome non-lethal skin disorders. Filaggrin plays a crucial role in the pathophysiology of barrier disruption in AD, interacting with inflammatory mediators. It is an integral part of the extracellular matrix architecture, serving to protect the skin barrier and attenuate the inflammatory cascade. In this study, we engineered a novel recombinant human filaggrin (rhFLA-10) expression vector, which was subsequently synthesized and purified. In vitro and ex vivo efficacy experiments were conducted for AD. rhFLA-10, at low concentrations (5 to 20 µg/mL), was non-toxic to HACaT cells, significantly inhibited the degranulation of P815 mast cells, and was readily absorbed by cells, thereby exerting a soothing therapeutic effect. Furthermore, rhFLA-10 demonstrated anti-inflammatory properties (p < 0.05). In vivo, efficacy experiments further substantiated that rhFLA-10 could effectively ameliorate AD in mice and facilitate the repair of damaged skin (p < 0.001). These findings underscore the considerable potential of rhFLA-10 in the treatment of AD.

3.
Chem Sci ; 15(15): 5482-5495, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38638208

ABSTRACT

In quantum dot-sensitized solar cells (QDSCs), optimized quantum dot (QD) loading mode and high QD loading amount are prerequisites for great device performance. Capping ligand-induced self-assembly (CLIS) mode represents the mainstream QD loading strategy in the fabrication of high-efficiency QDSCs. However, there remain limitations in CLIS that constrain further enhancement of QD loading levels. This review illustrates the development of various QD loading methods in QDSCs, with an emphasis on the outstanding merits and bottlenecks of CLIS. Subsequently, thermodynamic and kinetic factors dominating QD loading behaviors in CLIS are analyzed theoretically. Upon understanding driving forces, resistances, and energy effects in a QD assembly process, various novel strategies for improving the QD loading amount in CLIS are summarized, and the related functional mechanism is established. Finally, the article concludes and outlooks some remaining academic issues to be solved, so that higher QD loading amount and efficiencies of QDSCs can be anticipated in the future.

4.
ChemSusChem ; 17(11): e202301761, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38308586

ABSTRACT

Inorganic cesium lead halide perovskites (CsPbIxBr3-x, 0≤x≤3) are promising alternatives with great thermal stability. Additionally, the choice of moisture-resistive and dopant-free carbon as the electrode material can simultaneously solve the problems of stability and cost. Therefore, carbon electrode-based inorganic PSCs (C-IPSCs) represent a promising candidate for commercialization, yet both the efficiencies and stability of related devices demand further progress. This article reviews the recent advancement of C-IPSCs and then unravels the distinctive merits and limitations in this field. Subsequently, our perspective on various modification strategies is analyzed on a methodological level. Finally, this article outlooks the promising research contents and the remaining unresolved issues in this field. We believe that understanding and analyzing the related problems in this field are instructive to stimulate the future development of C-IPSCs.

5.
Microb Biotechnol ; 16(10): 1957-1970, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37556171

ABSTRACT

Toxoplasma gondii is a ubiquitous pathogen that infects all warm-blooded animals, including humans, causing substantial socioeconomic and healthcare burdens. However, there is no ideal vaccine for toxoplasmosis. As metabolism is important in the growth and virulence of Toxoplasma, some key pathways are promising antiparasitic targets. Here, we identified 6-phosphogluconate dehydrogenase 1 (Tg6PGDH1) in the oxidative pentose phosphate pathway as a cytoplasmic protein that is dispensable for tachyzoite growth of T. gondii in vitro but critical for virulence and cyst formation in vivo. The depletion of Tg6PGDH1 causes decreased gene transcription involved in signal transduction, transcriptional regulation and virulence. Furthermore, we analysed the protective effect of the ME49Δ6pgdh1 mutant as an attenuated vaccine and found that ME49Δ6pgdh1 immunization stimulated strong protective immunity against lethal challenges and blocked cyst formation caused by reinfection. Furthermore, we showed that ME49Δ6pgdh1 immunization stimulated increased levels of interferon-gamma, tumour necrosis factor-alpha and Toxoplasma-specific IgG antibodies. These data highlight the role of Tg6PGDH1 in the growth and virulence of T. gondii and its potential as a target for the development of a live-attenuated vaccine.

6.
Angew Chem Int Ed Engl ; 62(25): e202303486, 2023 Jun 19.
Article in English | MEDLINE | ID: mdl-37186501

ABSTRACT

Defects in perovskite are key factors in limiting the photovoltaic performance and stability of perovskite solar cells (PSCs). Generally, choline halide (ChX) can effectively passivate defects by binding with charged point defects of perovskite. However, we verified that ChI can react with CsPbI3 to form a novel crystal phase of one-dimensional (1D) ChPbI3 , which constructs 1D/3D heterostructure with 3D CsPbI3 , passivating the defects of CsPbI3 more effectively and then resulting in significantly improved photoluminescence lifetime from 20.2 ns to 49.4 ns. Moreover, the outstanding chemical inertness of 1D ChPbI3 and the repair of undesired δ-CsPbI3 deficiency during its formation process can significantly enhance the stability of CsPbI3 film. Benefiting from 1D/3D heterostructure, CsPbI3 carbon-based PSCs (C-PSCs) delivered a champion efficiency of 18.05 % and a new certified record of 17.8 % in hole transport material (HTM)-free inorganic C-PSCs.


Subject(s)
Calcium Compounds , Carbon , Choline , Oxides
7.
Small ; 19(29): e2300690, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37035984

ABSTRACT

Titanium oxide (TiO2 ) has been widely used as an electron transport layer (ETL) in perovskite solar cells (PSCs). Typically, TiCl4 post-treatment is indispensable for modifying the surfaces of TiO2 ETL to improve the electron transport performance. However, it is challenging to produce the preferred anatase phase-dominated TiO2 by the TiCl4 post-treatment due to the higher thermodynamic stability of the rutile phase. In this work, a mild continuous pH control strategy for effectively regulating the hydrolysis process of TiCl4 post-treatment is proposed. As the weak organic base, urea has been demonstrated can maintain a moderate pH decrease during the hydrolysis process of TiCl4 while keeping the hydrolysis process relatively mild due to the ultra-weak alkalinity. The improved pH environment is beneficial for the formation of anatase TiO2 . Consequently, a uniform anatase-dominated TiO2 surface layer is formed on the mesoporous TiO2 , resulting in reduced defect density and superior band energy level. The interfacial charge recombination is effectively suppressed, and the charge extraction efficiency is improved simultaneously in the fabricated solar cells. The efficiency of the fabricated carbon electrode-based PSCs (C-PSCs) is improved from 16.63% to 18.08%, which is the highest for C-PSCs based on wide-bandgap perovskites.

8.
Angew Chem Int Ed Engl ; 62(22): e202302342, 2023 May 22.
Article in English | MEDLINE | ID: mdl-37000423

ABSTRACT

Perovskite film with high crystal quality is fundamental to achieving high-performance solar cells. A fast nucleation process is crucial to improving the crystallization quality. Here, we propose a self-driven prenucleation strategy to achieve fast nucleation. This is realized through rational solvent design. The key characteristics of different solvents are systematically evaluated. Among them, formamide, with ultra-high dielectric constant, low Gutman donor number, and a high boiling point, is selected as the co-solvent. These unique characteristics render formamide a double-face solvent that is a good solvent for formamidinium iodide (FAI) and CsI while a poor solvent for PbI2 . As a result, formamide induces the self-driven prenucleation of PbI2 -DMSO seeding crystals and accelerates the nucleation, improving the crystalline quality of perovskite film. The efficiency of the hole transport layer-free carbon-based perovskite solar cells is boosted beyond 19 % for the first time.

9.
Adv Mater ; 34(40): e2206222, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35998374

ABSTRACT

Large energy loss (Eloss ) caused by defect-assisted recombination makes the photovoltaic performance of carbon-based perovskite solar cells (C-PSCs) inferior to that of metal-electrode ones. Herein, the influence of environmental factors (moisture and oxygen) on defect management during re-annealing process of CsPbI2 Br crystalline films is systematically studied. Density functional theory and experimental results indicate that moisture in the air can significantly reduce the oxidation kinetics of crystalline films, resulting in orderly oxidation. Concomitantly, the oxidation decomposition products PbO and CsPbIBr2 are enriched at grain boundaries, passivating surface defects efficiently. Simultaneously, energy band coupling between CsPbI2 Br and CsPbIBr2 improves the hole extraction efficiency. The photovoltage of corresponding C-PSCs is increased from 1.05 to 1.32 V, indicating a reduced Eloss derived from orderly oxidation strategy. Correspondingly, the champion cell achieves an efficiency of 15.27%, and a certified efficiency of 14.7%, which is a new record efficiency for CsPbI2 Br C-PSCs.

10.
Chem Rev ; 122(3): 4091-4162, 2022 02 09.
Article in English | MEDLINE | ID: mdl-34968050

ABSTRACT

Colloidal nanocrystals (NCs) are intriguing building blocks for assembling various functional thin films and devices. The electronic, optoelectronic, and thermoelectric applications of solution-processed, inorganic ligand (IL)-capped colloidal NCs are especially promising as the performance of related devices can substantially outperform their organic ligand-capped counterparts. This in turn highlights the significance of preparing IL-capped NC dispersions. The replacement of initial bulky and insulating ligands capped on NCs with short and conductive inorganic ones is a critical step in solution-phase ligand exchange for preparing IL-capped NCs. Solution-phase ligand exchange is extremely appealing due to the highly concentrated NC inks with completed ligand exchange and homogeneous ligand coverage on the NC surface. In this review, the state-of-the-art of IL-capped NCs derived from solution-phase inorganic ligand exchange (SPILE) reactions are comprehensively reviewed. First, a general overview of the development and recent advancements of the synthesis of IL-capped colloidal NCs, mechanisms of SPILE, elementary reaction principles, surface chemistry, and advanced characterizations is provided. Second, a series of important factors in the SPILE process are offered, followed by an illustration of how properties of NC dispersions evolve after ILE. Third, surface modifications of perovskite NCs with use of inorganic reagents are overviewed. They are necessary because perovskite NCs cannot withstand polar solvents or undergo SPILE due to their soft ionic nature. Fourth, an overview of the research progresses in utilizing IL-capped NCs for a wide range of applications is presented, including NC synthesis, NC solid and film fabrication techniques, field effect transistors, photodetectors, photovoltaic devices, thermoelectric, and photoelectrocatalytic materials. Finally, the review concludes by outlining the remaining challenges in this field and proposing promising directions to further promote the development of IL-capped NCs in practical application in the future.


Subject(s)
Nanoparticles , Electronics , Ligands , Nanoparticles/chemistry
11.
Article in English | MEDLINE | ID: mdl-34241587

ABSTRACT

A novel bacterial strain, designated K2CV101002-2T, was isolated from forest soil collected at Dinghushan Biosphere Reserve, Guangdong Province, PR China. Phylogenetic analyses based on 16S rRNA gene sequences showed that it belonged to the genus Chitinophaga and was most closely related to Chitinophaga terrae KP01T (99.0 %), followed by Chitinophaga extrema Mgbs1T (98.3 %) and Chitinophaga solisilvae O9T (98.1 %). The draft genome sequence was 6.8 Mb long with a relative low G+C content of 39.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between the novel strain and closely related type strains were 71.4‒76.2 % and 18.4‒19.6 %, respectively. Meanwhile the corresponding values between C. extrema Mgbs1T and C. solisilvae O9T were 98.6 and 88.1 %, respectively. The novel strain contained iso-C15:0, C16:1 ω5c and iso-C17:0 3-OH as the major fatty acids and MK-7 as the predominant respiratory quinone. The polyphasic study clearly supported that strain K2CV101002-2T represents a new species of the genus Chitinophaga, for which the name Chtinophaga silvatica sp. nov. (type strain K2CV101002-2T=GDMCC 1.1288T=JCM 32696T) is proposed. In addition, Chitinophaga extrema Goh et al. 2020 should be taken as a later heterotypic synonym of Chitinophaga solisilvae Ping et al. 2020.


Subject(s)
Bacteroidetes/classification , Forests , Phylogeny , Soil Microbiology , Bacterial Typing Techniques , Bacteroidetes/isolation & purification , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistry
12.
ACS Appl Mater Interfaces ; 13(26): 30746-30755, 2021 Jul 07.
Article in English | MEDLINE | ID: mdl-34170655

ABSTRACT

Lithium-sulfur batteries (LSBs) have been considered as potential next-generation energy storage systems due to their high specific energy of 2600 Wh kg-1 and 2800 Wh L-1. Nevertheless, the practical application of LSBs still faces several hazards, including the shuttle effect of soluble lithium polysulfides, low electrical conductivities of solid sulfur and lithium sulfides, and large volume expansion during charge/discharge cycles. To address this critical challenge, we innovatively proposed facile synthesis of nanostructured VN quantum dots (VNQD)/holey graphene matrix for stabilizing the sulfur cathode by simultaneously promoting the trapping, anchoring, and catalyzing efficiencies of both LiPSs and Li2S. Benefiting from abundant edge catalytic sites of VNQD, in-plane nanopores of graphene, and high electrical conductivity, the sulfur host not only provides high adsorption capability toward soluble polysulfides, strong binding ability for anchoring solid Li2S, and their rapid conversion kinetics but also contributes abundant sulfur storage sites and efficient transport pathways for lithium ions (Li+) and electrons. Consequently, the sulfur cathode exhibits high initial capacities of 1320 mAh g-1, high rate capability (850 mAh g-1 @ 4 mA cm-2), and high capacity retention of 99.95% per cycle after 500 cycles, providing a feasible solution for the practical utilization of shuttle-free Li-S batteries.

13.
J Am Chem Soc ; 143(12): 4790-4800, 2021 Mar 31.
Article in English | MEDLINE | ID: mdl-33734670

ABSTRACT

Low loading is one of the bottlenecks limiting the performance of quantum dot sensitized solar cells (QDSCs). Although previous QD secondary deposition relying on electrostatic interaction can improve QD loading, due to the introduction of new recombination centers, it is not capable of enhancing the photovoltage and fill factor. Herein, without the introduction of new recombination centers, a convenient QD secondary deposition approach is developed by creating new adsorption sites via the formation of a metal oxyhydroxide layer around QD presensitized photoanodes. MgCl2 solution treated Zn-Cu-In-S-Se (ZCISSe) QD sensitized TiO2 film electrodes have been chosen as a model device to investigate this secondary deposition approach. The experimental results demonstrate that additional 38% of the QDs are immobilized on the photoanode as a single layer. Due to the increased QD loading and concomitant enhanced light-harvesting capacity and reduced charge recombination, not only photocurrent but also photovoltage and fill factor have been remarkably enhanced. The average PCE of resulted ZCISSe QDSCs is boosted to 15.31% (Jsc = 26.52 mA cm-2, Voc = 0.802 V, FF = 0.720), from the original 13.54% (Jsc = 24.23 mA cm-2, Voc = 0.789 V, FF = 0.708). Furthermore, a new certified PCE record of 15.20% has been obtained for liquid-junction QDSCs.

14.
ChemSusChem ; 14(4): 1131-1139, 2021 Feb 18.
Article in English | MEDLINE | ID: mdl-33411408

ABSTRACT

Photocatalytic reduction of CO2 into value-added chemical fuels is an appealing approach to address energy crisis and global warming. CsPbBr3 quantum dots (QDs) are good candidates for CO2 reduction because of their excellent photoelectric properties, including high molar extinction coefficient, low exciton binding energy, and defect tolerance. However, the pristine CsPbBr3 QDs generally have low photocatalytic performance mainly due to dominant charge recombination and lack of efficient catalytic sites for CO2 adsorption/activation. Herein, we report a new photocatalytic system, in which CsPbBr3 QDs are coupled with covalent triazine frameworks (CTFs) for visible-light-driven CO2 reduction. In this hybrid photocatalytic system, the robust triazine rings and periodical pore structures of CTFs promote the charge separation in CsPbBr3 and endow them with strong CO2 adsorption/activation capacity. The resulting photocatalytic system exhibits excellent photocatalytic activity towards CO2 reduction. This work presents a new photocatalytic system based on CTFs and perovskite QDs for visible-light-driven CO2 reduction, which highlights the potential of perovskite-based photocatalysts for solar fuel applications.

15.
Angew Chem Int Ed Engl ; 60(2): 660-665, 2021 Jan 11.
Article in English | MEDLINE | ID: mdl-32964638

ABSTRACT

Lead-free CsSnX3 perovskite NCs are becoming a promising alternative to CsPbX3 (X=Cl, Br, I), but suffer from extremely poor stability. Herein, we highlight the significant effect of SnII precursors used in the synthesis on the stability of the resultant CsSnX3 NCs. A method is proposed for synthesizing CsSnX3 NCs using Cs2 CO3 , SnC2 O4 , and NH4 X as corresponding constituent precursors, wherein the ratio of reactants can be easily adjusted. Stable CsSnX3 NCs can be obtained with the use of antioxidative SnC2 O4 as the SnII precursor. Experimental results show that the improvement of NCs stability is mainly ascribed to the role of oxalate in the SnC2 O4 precursor. Oxalate ion has a strong antioxidative ability and can effectively inhibit the oxidation of SnII during the synthesis. Besides, oxalate as a bidentate capping ligand is shown to be coordinated on the surface of formed NCs. This can not only passivate the uncoordinated Sn on the surface but also prevent the oxidation of the NCs.

16.
Angew Chem Int Ed Engl ; 60(11): 6137-6144, 2021 Mar 08.
Article in English | MEDLINE | ID: mdl-33258189

ABSTRACT

The photoelectronic properties of quantum dots (QDs) have a critical impact on the performance of quantum-dot-sensitized solar cells (QDSCs). Currently, I-III-VI group QDs have become the mainstream light-harvesting materials in high-performance QDSCs. However, it is still a great challenge to achieve satisfactory efficiency for light-harvesting, charge extraction, and charge collection simultaneously in QDSCs. We design and prepare Zn0.4 Cu0.7 In1.0 Sx Se2-x (ZCISSe) quinary alloyed QDs by cation/anion co-alloying strategy. The critical photoelectronic properties of target QDs, including band gap, conduction band energy level, and density of defect trap states, can be conveniently tailored. Experimental results demonstrate that the ZCISSe quinary alloyed QDs can achieve an ideal balance among light-harvesting, photogenerated electron extraction, and charge-collection efficiencies in QDSCs compared to its single anion or cation quaternary alloyed QD counterparts. Consequently, the quinary alloyed QDs boost the certified efficiency of QDSCs to 14.4 %, which is a new efficiency record for liquid-junction QD solar cells.

17.
ACS Appl Mater Interfaces ; 12(39): 43844-43853, 2020 Sep 30.
Article in English | MEDLINE | ID: mdl-32897698

ABSTRACT

Lithium-sulfur (Li-S) batteries have shown great potential in the next-generation energy storage devices due to high theoretical energy density and low cost. To obtain high-performance Li-S batteries, it is important to inhibit the polysulfide shuttle effect and improve the reaction kinetics of polysulfides. Herein, CoP nanoparticles coated by metal-organic framework-derived N-doped mesoporous carbon (CoP@N-C) composites are synthesized and applied in both a cathode for a sulfur host and a modified layer on a separator for high-energy-density Li-S batteries since the CoP component has strong chemical anchoring capability toward soluble polysulfides and high electrochemical activity toward polysulfides transformation. Meanwhile, the porous structure of conductive N-doped mesoporous carbon can not only buffer the volume variation of sulfur during the charge/discharge process but also enhance the charge transport rate in the cathode. The constructed batteries have demonstrated a high specific capacity of 1222 mAh g-1 (8.6 mAh cm-2) with a high sulfur areal loading of ∼7.0 mg cm-2 on cathodes, and a mass loading of 0.35 mg cm-2 for modified layer on separators. Its average capacity decay is only 0.076% per cycle after 100 cycles. This work presents the highly competitive performance of Li-S batteries on the areal capacity and capacity decay.

18.
ACS Appl Mater Interfaces ; 12(18): 20579-20588, 2020 May 06.
Article in English | MEDLINE | ID: mdl-32272011

ABSTRACT

For converting the renewable solar energy to hydrogen (H2) energy by photocatalytic (PC) overall water splitting (OWS), visible-light-driven photocatalysts are especially desired. Herein, a model CdS/g-C3N4 photocatalyst with a type II heterojunction is first demonstrated via a facile coupling of g-C3N4 nanosheets and CdS nanorods. After being combined with in situ photodeposited 3 wt % Pt and 4 wt % MnOx dual cocatalysts simultaneously, the optimal visible-light-driven (λ > 400 nm) composite photocatalyst of Pt-CdS/g-C3N4-MnOx gives a H2 generation rate of 9.244 µmol h-1 (924.4 µmol h-1 g-1) and a O2 evolution rate of 4.6 µmol h-1 (460 µmol h-1 g-1) in pure water, which is over 420 times higher than that of pure CdS nanorods loaded with 0.5 wt % Pt. The apparent quantum efficiency (AQE) reaches about 3.389% (at 400 nm) and 1.745% (at 420 nm), respectively. The combination of a type II heterojunction and simultaneous in situ photodeposition of the dual cocatalysts results in a dramatically improved PC efficiency and a long-term stability of the CdS/g-C3N4 visible-light-driven photocatalyst for OWS.

19.
Adv Mater ; 31(49): e1903696, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31621961

ABSTRACT

Generally, high light-harvesting efficiency, electron-injection efficiency, and charge-collection efficiency are the prerequisites for high-efficiency quantum-dot-sensitized solar cells (QDSCs). However, it is fairly difficult for a single QD sensitizer to meet these three requirements simultaneously. It is demonstrated that these parameters can be felicitously balanced by a cosensitization strategy through the adoption of environmental-friendly Zn-Cu-In-Se and Zn-Cu-In-S dual QD sensitizers with cascade energy structure. Experimental results indicate that: i) the combination of the dual QDs can improve the light-harvesting capability of the cells, especially in the visible light window; ii) the cosensitization approach can facilitate electron injection, benefitting from the cascade energy structure of the two QD sensitizers employed; iii) the charge-collection efficiency can be remarkably enhanced by the suppressed charge-recombination process due to the improved QD coverage on TiO2 . Consequently, this cosensitization strategy delivers a new certified efficiency record of 12.98% for liquid-junction QDSCs under AM 1.5G 1 sun irradiation. Moreover, the constructed cells exhibit good stability in a high-humidity environment.

20.
ACS Appl Mater Interfaces ; 11(44): 41415-41423, 2019 Nov 06.
Article in English | MEDLINE | ID: mdl-31613581

ABSTRACT

Interface modification is an important means for improving the performance of almost all optoelectronic devices. In quantum-dot-sensitized solar cells (QDSCs), effective surface modification of photoanode also has a critical impact on photovoltaic performance. At present, ZnS and ZnSe wide band gap semiconductors are the mainstream materials used for photoanode/electrolyte interface passivation in QDSCs. However, the problem with these two materials is that the passivation effect and the lattice match with TiO2/QD are difficult to be balanced. Although ZnS can form a larger energetic barrier due to the higher conduction band edge, its lattice mismatch with TiO2 and QD (such as CdSe and CuInSe2) is large, leading to the formation of additional defect states. On the contrary, ZnSe has a small lattice mismatch with TiO2 and QD but a relatively lower conduction band edge. Herein, we propose a strategy to employ ZnSxSe1-x alloy materials as a passivation layer for the first time to solve the drawbacks of single-component passivation layers. The ZnSxSe1-x alloy passivation layer was deposited on the Zn-Cu-In-Se (ZCISe) QD-sensitized TiO2 film electrode via successive ionic layer adsorption and reaction (SILAR) method. A stable polyselenosulfide/sulfide mixed anions were served as anion precursor for the formation of ZnSxSe1-x alloy passivation layer. Experimental results revealed that the alloy passivation layer is more favorable for the suppression of charge recombination at the photoanode/electrolyte interface. In addition, the ZnSxSe1-x alloy passivation layer can significantly improve the photogenerated electron extraction efficiency compared to the current classical ZnS passivation layer as confirmed by the transient absorption (TA) measurement. Consequently, the average efficiency of QDSCs was improved from 12.17 to 13.08% with the replacement of traditional ZnS passivation layer by ZnSSe-10 under AM 1.5G one full sun illumination.

SELECTION OF CITATIONS
SEARCH DETAIL
...