Efficient extraction of photogenerated charge carriers is of significance for acquiring a high efficiency for perovskite solar cells. In this paper, a systematic strategy for effectively engineering ...the charge extraction in inverted structured perovskite solar cells based on methylammonium lead halide perovskite (CH 3 NH 3 PbI 3−x Cl x ) is presented. Intentionally doping the chlorine element into the perovskite structure is helpful for obtaining a high open circuit voltage. The engineering is carried out by modifying the aluminium cathode with zirconium acetylacetonate, doping the hole transport layer of nickel oxide (NiO x ) with copper and using an advanced fluorine doped tin oxide (FTO) substrate. This improves the bandgap alignment of the whole device, and thus, is of great benefit for extracting the charge carriers by promoting the transport rate and reducing the trap states. Consequently, an optimized power conversion efficiency of 20.5% is realized. Insights into how to extract charge carriers efficiently with a minimum energy loss are discussed.
Polymer solar cells have shown good prospect for development due to their advantages of low-cost, light-weight, solution processable fabrication, and mechanical flexibility. Their compatibility with ...the industrial roll-to-roll manufacturing process makes it superior to other kind of solar cells. Normally, indium tin oxide (ITO) is adopted as the transparent electrode in polymer solar cells, which combines good conductivity and transparency. However, some intrinsic weaknesses of ITO restrict its large scale applications in the future, including a high fabrication price using high temperature vacuum deposition method, scarcity of indium, brittleness and scaling up of resistance with the increase of area. Some substitutes to ITO have emerged in recent years, which can be used in flexible polymer solar cells. This article provides the review on recent progress using other transparent electrodes, including carbon nanotubes, graphene, metal nanowires and nanogrids, conductive polymer, and some other electrodes. Device stability is also discussed briefly.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Manipulating stimulated‐emission processes and overcoming the ohmic loss of metals in plasmonic lasers are of significance for the according applications in biological sensors, data storage, ...photolithography, and optical communications. Herein, through utilizing an electrochemical‐assisted growth method for high‐quality perovskite nanowires, plasmonic lasers based on the structure of metal/dielectric layer/perovskite nanowires are constructed. The plasmonic lasers demonstrate a threshold of 62 µJ cm−2, a high quality factor of Q ≈ 655, and a fast lasing decay time of 1.6 ps. Interestingly, the plasmonic lasers present an attractive capability in transformation from single mode to multiple modes just by adjusting the pumping energy. In addition to the broad stoichiometry‐dependent tunability of the perovskite materials, the proposed plasmonic lasers have great promise in real applications.
Plasmonic lasers based on the structure of metal/dielectric layer/perovskite nanowires are constructed via an electrochemical‐assisted growth method for high‐quality perovskite nanowires. The plasmonic lasers demonstrate a threshold of 62 µJ cm−2, a high quality factor of ≈655, and a fast lasing decay time of 1.6 ps. The laser modes can be effectively manipulated by adjusting the pump energy.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lead halide perovskites have gained tremendous attentions in many fields, especially in nanolasers, owing to the excellent optoelectronic properties. However, the underlying lasing mechanism is not ...clear in both plasmonic and photonic nanolasers at room temperature. Here, the plasmonic lasers and the photonic counterparts based on organic–inorganic hybrid lead tri‐bromine perovskite nanowires are achieved at room temperature and are compared in terms of lasing evolution, lasing wavelengths, and lasing dynamics. The same spectra evolution and the same emission wavelength indicate that the plasmonic and the photonic CH3NH3PbBr3 nanowire lasers have the same gain origination. The calculated Mott density lower than the threshold density and lasing photon energy lower than exciton energy prove that an electron–hole plasma contributes to both the two types of lasing actions from perovskite nanowires at room temperature. The work deepens the understanding of underlying mechanism of perovskite nanowire lasers.
An electron–hole plasma is responsible for the plasmonic and photonic lasing in single‐crystal CH3NH3PbBr3 nanowires at room temperature owing to lower emission energy than exciton resonance and the higher threshold density than the Mott density.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Electrically pumped nanolasers have achieved many exciting achievements and display a wide range of potential application prospects in the fields of optoelectronic chips, information storage, and ...biosensing. However, there is lacking an in‐depth and extensive review of the recent development of electrically pumped nanolasers. Herein, a detailed and comprehensive overview of the electrically pumped nanolasers is first given according to the device configurations, including electrically pumped single nanolaser, nanoarray lasers, nanobeam lasers, and plasmonic nanolasers with different cavity structures. Furthermore, some problems and challenges restricting the development of electrically pumped nanolasers are summarized, and the corresponding solutions and development directions are proposed. This review will provide valuable suggestions for optimizing the device structure of electrically pumped nanolasers with new high‐gain semiconductor materials and particularly further promote their rapid application development.
This review gives a detailed and comprehensive overview of the electrically pumped nanolasers according to the device configurations, including electrically pumped single nanolaser, nanoarray lasers, nanobeam lasers, and plasmonic nanolasers with different cavity structures. Furthermore, some problems and challenges restricting the development of electrically pumped nanolasers are summarized, and the corresponding solutions and development directions are also proposed.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
The electrodeposition method has recently been developed for the fabrication of perovskite solar cells due to its potential advantages in commercial preparation. However, there is few ...studies on the preparation of perovskite solar cells by the electrodeposition method, especially on the perovskite FAPbI
3
-based solar cells. Herein, we fabricated the mixed perovskite FA
1−
y
Cs
y
PbBr
x
I
3−
x
solar cells by an optimized electrodeposition method, in which the electrodeposited PbO
2
reacts directly with FAI and an appropriate amount of CsBr dopants. The corresponding solar cells display the best PCE of 4.97%. By regulating the growth temperature in the reaction between PbO
2
and FAI/CsBr, the efficiency of the mixed perovskite solar cells can be promoted to 10.18%. These results illustrate that the element doping and growth environment regulation can optimize the quality of the perovskite films, thus promoting the efficiency of the perovskite solar cells. With further optimizing the growth process in the electrodeposition method, it is expected to open up a new commercial preparation route for the perovskite solar cells in the near future.
The Z-scheme heterojunction photocatalysts possess excellent photocatalytic activity benefitting from their properly matched edge potentials. In this work, ZnCo2S4 nanoparticles are anchored on ...Zn0.2Cd0.8S solid solution nanowires and assembled into binary ZnCo2S4/Zn0.2Cd0.8S nanocomposites. The as-synthesized ZnCo2S4/Zn0.2Cd0.8S nanocomposites act as bifunctional photocatalysts, which can be used for high-performance H2 production coupling synthesis of high-value-added benzaldehyde in low concentration benzyl alcohol solution. Under visible light irradiation, 20%-ZnCo2S4/Zn0.2Cd0.8S nanocomposite shows the highest H2 evolution rate of 23.02 mmol g−1 h−1 in the first photocatalytic cycle, which is 395.0 and 526.7 times higher than that of Zn0.2Cd0.8S and ZnCo2S4 under the same conditions. Eventually, after six-time cycles, the conversion rate and selectivity of benzyl alcohol oxidation to benzaldehyde are 54.3% and 92.2%, respectively. The enhancement of photocatalytic performance is mainly attributed to the Z-scheme heterojunction between ZnCo2S4 and Zn0.2Cd0.8S, which promote the separation and transfer of photogenerated charge carriers. This work provides strong support for the rational design of Z-scheme nano-heterojunction of highly efficient photocatalytic application in H2 evolution and fine chemicals production.
The bifunctional ZnCo2S4/Zn0.2Cd0.8S Z-scheme heterojunction photocatalysts show efficient H2 evolution rate and high-value-added benzaldehyde synthesis activity under visible light irradiation. Display omitted
•An efficient bifunctional ZnCo2S4/Zn0.2Cd0.8S heterojunction is prepared.•ZnCo2S4/Zn0.2Cd0.8S shows excellent H2 evolution and benzaldehyde synthesis activity.•The photocatalytic mechanism between ZnCo2S4 and Zn0.2Cd0.8S is proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Utilizing photocatalytic technology to efficiently convert biomass-derived compounds into value-added chemicals and release hydrogen gas can effectively address energy and environmental issues. For ...this purpose, we fabricated a series of NiMoS4/Zn0.6Cd0.4S nanocomposites through a simple two-pot hydrothermal treatment. Dexterously, the photoexcited electrons and holes can be simultaneously utilized to participate in a photocatalytic redox reaction, effectively achieving the oxidation of furfuryl alcohol while cooperating with H2 evolution. The hydrogen evolution rate of 10%-NiMoS4/Zn0.6Cd0.4S nanocomposite in 1.50 vol % furfuryl alcohol aqueous solution is as high as 289.5 μmol·h–1, which is approximately 2895 and 41 times higher than that of pure NiMoS4 and Zn0.6Cd0.4S, respectively. Meanwhile, after 13 cycles of photocatalytic reaction, the conversion efficiency and selectivity of converting furfuryl alcohol to furfural are 68.5% and 94.0%, respectively. This photocatalyst also shows high photocurrent, low impedance, and efficient photogenerated carrier separation and transport properties, which can be attributed to the establishment of an ohmic junction between NiMoS4 and Zn0.6Cd0.4S. It is anticipated that this work can provide inspiration for the effective conversion of biomass-derived platform chemicals into high-value chemicals through visible-light-driven photocatalytic technology.
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IJS, KILJ, NUK, PNG, UL, UM
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