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A photovoltaic photodetector based on a hybrid dimensional WSe2/WS2/p-Si dual-vdW heterojunction is constructed, which can realize the coupling of the photovoltaic effect and photogating effect.

High-performance visible and near-infrared photodetection and single-pixel imaging can be achieved by our γ-InSe/Ge photodiode at zero bias. Meanwhile, a maximum polarization sensitivity of 3.01 is obtained under 635 nm among the broadband spectrum.

The Te/SnS2 tunneling heterojunctions possess interesting type-III band alignment and reverse rectification feature, which can work as high-performance photodetector with excellent self-powered performance.

Two-dimensional (2D) polarization-sensitive detection as a new photoelectric application technology is extensively investigated. However, most devices are mainly based on individual anisotropic materials, which suffer from large dark current and relatively low anisotropic ratio, limiting the practical application in polarized imaging system. Herein, we design a van der Waals (vdWs) p-type SnS/n-type InSe vertical heterojunction with proposed type-II band alignment

A Te/Si heterojunction photodetector array has been in situ constructed by performing pulsed-laser deposition of a Te nanofilm on a pre-patterned 2-inch SiO2/Si wafer, exhibiting ultra-broadband photosensitivity from ultraviolet to infrared.

A hierarchical SnS/ZnIn2S4 heterostructure with optical regulation and band tailoring is developed for high-performance broadband integrated optoelectronics.

Two-dimensional (2D) materials have attracted widespread research attention toward multiple optoelectronic applications, owing to their promising sensitivity to light. However, the weak light absor...

With the fast development of semiconductor technology, self-driven devices have become an indispensable part of modern electronic and optoelectronic components. In this field, in addition to traditional Schottky and p–n junction devices, hybrid 2D/3D semiconductor heterostructures provide an alternative platform for optoelectronic applications. Herein we report the growth of 2D SnS1−xSex (x = 0, 0.5, 1) nanosheets and the construction of a hybrid SnS0.5Se0.5/GaAs heterostructure based self-driven photodetector. The strong anisotropy of 2D SnS1−xSex is demonstrated theoretically and experimentally. The self-driven photodetector shows high sensitivity to incident light from the visible to near-infrared regime. At the wavelength of 405 nm, the device enables maximum responsivity of 10.2 A W−1, high detectivity of 4.8 × 1012 Jones and fast response speed of 0.5/3.47 ms. Impressively, such a heterostructure device exhibits anisotropic photodetection characteristics with the dichroic ratio of ∼1.25 at 405 nm and ∼1.45 at 635 nm. These remarkable features can be attributed to the high-quality built-in potential at the SnS0.5Se0.5/GaAs interface and the alloy engineering, which effectively separates the photogenerated carriers and suppresses the deep-level defects, respectively. These results imply the great potential of our SnS0.5Se0.5/GaAs heterostructure for high-performance photodetection devices.

In recent years, two-dimensional material-based tunneling heterojunctions are emerging as a multi-functional architecture for logic circuits and photodetection owing to the flexible stacking, optical sensitivity, tunable detection band, and highly controllable conductivity behaviors. However, the existing structures are mainly focused on transition or post-transition metal chalcogenides and have been rarely investigated as topological insulator (such as Bi2Se3 or Bi2Te3)-based tunneling heterostructures. Meanwhile, it is challenging to mechanically exfoliate the topological insulator thin nanoflakes because of the strong layer-by-layer interaction with shorter interlayer spacing. Herein, we report Au-assisted exfoliation and non-destructive transfer method to fabricate large-scale Bi2Se3 thin nanosheets. Furthermore, a novel broken-gap tunneling heterostructure is designed by combing 2H-MoTe2 and Bi2Se3via the dry-transfer method. Thanks to the realized band alignment, this ambipolar-n device shows a clear rectifying behavior at Vds of 1 V. A built-in potential exceeding ∼0.7 eV is verified owing to the large band offsets by comparing the numerical solution of Poisson's equation and the experimental data. Carrier transport is governed by the majority carrier including thermionic emission and the tunneling process through the barrier height. At last, the device shows an ultralow dark current of ∼0.2 pA and a superior optoelectrical performance of Ilight/Idark ratio ≈106, a fast response time of 21 ms, and a specific detectivity of 7.2 × 1011 Jones for a visible light of 405 nm under zero-bias. Our work demonstrates a new universal method to fabricate a topological insulator and paves a new strategy for the construction of novel van der Waals tunneling structures.

As we know, binary two-dimensional (2D) IVA–VIA monochalcogenides such as stannous sulfide (SnS) and stannous selenide (SnSe) possess an asymmetric crystalline structure perpendicular to the layer-...

Functional van der Waals (vdWs) heterostructures based on layered materials have shown tremendous potential in next-generation optoelectronic devices. To date, numerous vdWs heterostructures have been investigated based on stacking or epitaxial growth technology. However, the complicated synthesis process greatly limits the large-scale integration of the heterostructure device array, which is essential for practical applications. Here, a planar photodetector array with an out-of-plane vertical In2Se3/SnSe2 heterostructure as the photosensitive channel was self-assembled through a pulsed laser deposition (PLD) technique. The vertical built-in field was exploited to suppress the dark current and separate the photogenerated carriers. The realized devices possess an ultralow dark current of 6.3 pA, combined with a high detectivity of 8.8×1011 Jones and a high signal-to-noise ratio (SNR) beyond 3×104. These performance metrics not only are one order of magnitude superior to pure In2Se3 device, but also demonstrate the unique advantage of detecting weak signals. In addition, this heterostructure photodetector array can further be constructed on flexible polyimide (PI) substrate. These flexible devices also demonstrate effective light detection capability and the photoresponse remains unchanged even after 200 cycles of bending. These findings pave a way toward the development of next-generation large area and high integration optoelectronic technologies.

Recent years have seen swift increase in the power conversion efficiency of perovskite solar cells (PSCs). Interface engineering is a promising route for further improving the performance of PSCs. Here we perform first-principles calculations to explore the effect of four candidate buffer materials (MACl, MAI, PbCl2 and PbI2) on the electronic structures of the interface between MAPbI3 absorber and TiO2. We find that MAX (X = Cl, I) as buffer layers will introduce a high electron barrier and enhance the electron-hole recombination. Additionally, MAX does not passivate the surface states well. The conduction band minimum of PbI2 is much lower than that of MAPbI3 absorber, which significantly limits the band bending of the absorber and open-circuit voltage of solar cells. On the other side, suitable bandedge energy level positions, small lattice mismatch with TiO2 surfaces, and excellent surface passivation make PbCl2 a promising buffer material for absorber/electron-transport-layer interface engineering in PSCs. Our results in this work thus provide deep understanding on the effects of interface engineering with a buffer layer, which shall be useful for improving the performance of PSCs and related optoelectronics.

Self-powered photodetectors have triggered extensive attention in recent years due to the advantages of high sensitivity, fast response, low power consumption, high level of integration and wireless operation. To date, most self-powered photodetectors are implemented through the construction of either heterostructures or asymmetric electrode material contact, which are complex to process and costly to produce. Herein, for the first time, we achieved a self-powered operation by adopting a geometrical asymmetry in the device architecture, where a triangular non-layered 2D In2S3 flake with an asymmetric contact is combined with the traditional photogating effect. Importantly, the device achieves excellent photoresponsivity (740 mA W-1), high detectivity (1.56 × 1010 Jones), and fast response time (9/10 ms) under zero bias. Furthermore, the asymmetric In2S3/Si photodetector manifests long-term stability. Even after 1000 cycles of operation, the asymmetric In2S3/Si device displays negligible performance degradation. In sum, the above results highlight a novel route towards self-powered photodetectors with high performance, simple processing and structure in the future.

Non-layered 2D materials exhibit intriguing properties, widening the scope of 2D libraries and promising considerable potential for applications in next-generation optoelectronics. However, due to their surface dangling bonds and weak light adsorption arising from their atomically thin thickness, their photosensitivity is still limited. Herein, we achieve an ultrasensitive 2D In2S3 photodetector by adopting strain engineering coupled with optical regulation. A SiO2 nanograting array was introduced to construct a strained morphology of 2D In2S3. This morphology induces charge localization and renders a back-to-back built-in electric field array, which efficiently suppresses the dark current and separates the photo-excited carriers. Simultaneously, the SiO2 nanograting array realizes light management and improves its light harvesting. As a result, the device presents an ultralow dark current of 3.2 pA with a high signal-to-noise ratio of up to 1.7 × 106. In particular, a prominent photoresponsivity of 1810 A W−1, an excellent detectivity of 2.09 × 1015 Jones and a fast response speed of 0.41 ms are achieved. This work depicts an effective scheme to associate photonic/electronic property manipulation for optoelectronic applications.

Two-dimensional (2D) semiconductors with atomic layers, and a flat and active surface provide an attractive platform for the study of surface-enhanced Raman scattering (SERS). Many 2D layered materials, including graphene and transition metal dichalcogenide (TMD), have been exploited as potential Raman enhancers for SERS-based molecule sensing. Herein, atomically-thin palladium diselenide (PdSe

Low light absorption and limited carrier lifetime are two limiting factors hampering the further breakthrough of the performance of 2D materials (2DMs)-based photodetectors. This study proposes an ingenious dielectric engineering strategy toward boosting the photosensitivity. Periodic dielectric structures (PDSs), including SiO

Alloy engineering and heterostructures designing are two efficient methods to improve the photosensitivity of two-dimensional (2D) material-based photodetectors. Herein, we report the first-principle calculation about the band structure of SnS1-xSex (0 ≤ x ≤ 1) and synthesize these alloy nanosheets. Systematic measurements indicate that SnS0.25Se0.75 exhibits the highest hole mobility (0.77 cm2·V-1·s-1) and a moderate photoresponsivity (4.44 × 102 A·W-1) with fast response speed (32.1/57.5 ms) under 635 nm irradiation. Furthermore, to reduce the dark current and strengthen the light absorption, a self-driven SnS0.25Se0.75/n-Si device has been fabricated. The device achieved a preeminent photo-responsivity of 377 mA·W-1, a detectivity of ∼1011 Jones and Ilight/Idark ratio of ∼4.5 × 102. In addition, the corresponding rising/decay times are as short as 4.7/3.9 ms. Moreover, a broadband sensitivity from 635 to 1200 nm is obtained and the related photoswitching curves are stable and reproducibility. Noticeably, the above parameters are comparable or superior to the most of reported group IVA layered materials-based self-driven photodetectors. Last, the synergistic effects between the SnS0.25Se0.75 nanosheets and the n-Si have been discussed by the band alignment. These brilliant results will pave a new pathway for the development of next generation 2D alloy-based photoelectronic devices.

In recent years, photodetectors have very important applications in image sensing, optical communication, fire detection, environmental monitoring, space detection, safety detection, many other scientific research and industrial technology fields, which are regarded as the key components of wearable devices. Due to its great carrier mobility, high absorption coefficient and relatively narrower bandgap engineering, various of photodetector based on 2D group IVA metal chalcogenides, the corresponding ternary alloys and the heterostructures have been reported. Importantly, most of them basically have excellent performance of photodetecting properties, such as large photocurrent, high detectivity, perfect responsivity, high external quantum efficiency, short response and recovery time, broadband photo adsorption and response from ultraviolet to mid infrared range. Moreover, this group of semiconductors is made up of earth-abundant and environmental-friendly elements with prominent chemical stability, which makes them particularly attractive for practical optic electronic applications. Therefore, this concept introduces the recent advances on the materials, synthesis, device fabrication and photodetection mechanism for various of 2D group IVA metal chalcogenides photodetector from an overall perspective. Moreover, challenges and future development trends are discussed.

MoSe2/WSe2 two-dimensional transition-metal dichalcogenide (TMDC) heterojunction photodetectors based on epitaxial n-doped 4H-silicon carbide (SiC) substrate are investigated and exhibited low leakage, high stability, and fast photoresponse. The efficient separation of photogenerated carriers occurs between TMDCs and 4H-SiC, as indicated by the photoluminescence spectrum and the band alignment analysis under 532 nm. The MoSe2/WSe2/4H-SiC photodetector shows an obvious rectification behavior and unique current-gate voltage ( I- Vg) characteristics. The gate tunable photocurrent scanning maps display the highest photocurrent in the MoSe2/WSe2 region including a certain intensive current region in individual TMDCs/4H-SiC junctions under a 532 nm laser. Besides, the maximum responsivity of the heterojunction photodetectors is 7.17 A·W-1 with the Vg of 10 V at positive bias. The corresponding maximum external quantum efficiency and detectivity also significantly increase to 1.67 × 103% and 5.51 × 1011 jones with the largest Ilight/ Idark ratio of ∼103. Moreover, the MoSe2/4H-SiC photodetector delivers an enhanced photoresponse behavior with gate modulation, which is different from the previous paper. These results of our study demonstrate that MoSe2/WSe2 heterojunction photodetectors based on the n-doped 4H-SiC substrate will be a promising candidate for future optoelectronics applications in spectral responsivity.

Two-dimensional layers of metal dichalcogenides have attracted much attention because of their ultrathin thickness and potential applications in electronics and optoelectronics. In this regard, we further explore the optoelectronic properties of monolayer MoS2 synthesized by chemical vapor deposition on sapphire substrate and contacted the Au electrode by lithographie method for applications in photodetectors. The device exhibits broadband photoresponse (UV–Vis-NIR), a lower subthreshold swing (0.5 V), higher detectivity (1010 Jones) and superior responsivity (0.0084 A/W). We believe that this work provides important scientific insights for photoelectric response properties of emerging atomically layered 2D materials for optoelectronic applications.

In recent years, with the rapid development of transfer technologies related to graphene and other two-dimensional layered materials (2DLMs), graphene sandwiched 2DLMs have been confirmed to be outstanding tunneling and optoelectronic devices. Here, compared to the planar SnSe2-Au device, the SnSe2 device with different thicknesses (12-256 nm) is incorporated into graphene sandwiched structures for photodetection. The results indicate that the photoresponse properties are dependent on the thickness and gate voltage. In particular, under 532 nm illumination and at a Vg of +80 V, the SnSe2 device with a thickness of 96.5 nm shows an impressively high responsivity of 1.3 × 103 A W-1, an external quantum efficiency of 3 × 105%, and a detectivity of 1.2 × 1012 Jones. Besides, a high response speed (a rise time of 30.2 ms and a decay time of 27.2 ms) and flat photoswitching behavior are achieved without the gate voltage. In addition, the intrinsic mechanisms are further discussed through the relative spatial potential difference and the band alignment diagrams of the graphene-SnSe2-graphene and Au-SnSe2-Au structures. These findings indicate that SnSe2 has great potential for practical applications in next generation high performance optoelectronics.

Solar cell is a kind of devices for renewable and environmentally friendly energy conversion. One of the important things for solar cells is conversion efficiency. While much attention has been drawn to improving efficiency, the role of strain engineering in two-dimensional materials is not yet well-understood. Here, we propose a Pmc21-As monolayer that can be used as a solar cell absorbing material. The bandgap of single-layer Pmc21-As can be tuned from 1.83 to 0 eV by applying tensile strain, while keeping the direct bandgap characteristic. Moreover, it has high light absorption efficiency in the visible and near-infrared regions, which demonstrates a great advantage for improving the conversion efficiency of solar cells. Based on the tunable electronic and optical properties, a novel design strategy for solar cells with a wide absorption range and high absorption efficiency is suggested. Our results not only have direct implication in strain effect on two-dimensional materials, but also give a possible concept for improving the solar cell performance.

ispartof: MATERIALS & DESIGN vol:215 status: published

Structural and electronic properties of graphdiyne/MoS2 van der Waals (vdW) heterostructure under external electric field are investigated by first-principle calculations for the first time. The direct bandgap of graphdiyne/MoS2 heterostructure can be significantly modulated by the electric field, and a transition from semiconductor to metal is observed. It is demonstrated that the graphdiyne/MoS2 bilayer transfers from type-I to type-II heterostructure under a certain electric field, leading to the spatial separation of the lowest energy electron-hole pairs, which is beneficial to photodetection and solar energy conversion. The calculation results pave the way for applications of graphdiyne/MoS2 heterostructure in future micro-/nano- electronics and photoelectronics.

Schottky-barrier field-effect transistors (SBFETs) based on multilayer WS2 with Au as drain/source contacts are fabricated in this paper. Interestingly, the novel polarity behavior of the WS2 SBFETs can be modulated by drain bias, ranging from p-type to ambipolar and finally to n-type conductivity, due to the transition of band structures and Schottky-barrier heights under different drain and gate biases. The electron mobility and the on/off ratio of electron current can reach as high as 23.4 cm2/(V s) and 8.5 × 107, respectively. Moreover, the WS2 SBFET possesses high-performance photosensitive characteristics with response time of 40 ms, photoresponsivity of 12.4 A/W, external quantum efficiency of 2420%, and photodetectivity as high as 9.28 × 1011 cm Hz1/2/W. In conclusion, the excellent performance of the WS2 SBFETs may pave the way for next-generation electronic and photoelectronic devices.

Commercial photodetectors have been dominated by bulk silicon (B-Si) due to the maturity of Si technology. However, its relatively poor mobility has impeded B-Si from high-performance applications. Herein, we demonstrate that tin dioxide quantum dots (SnO2-QDs) coupled with graphene produce a Schottky junction with B-Si to drastically promote the performance of the SnO2-QDs/graphene/B-Si Schottky photodetector. This hybrid device is sensitive to broadband illumination covering the UV-vis-NIR region and shows high responsivity of 967.6 A W−1 (nearly 4 orders higher than that of commercial B-Si Schottky photodetectors), with corresponding external quantum efficiency of 2.3 × 105% and detectivity of 1.8 × 1013 Jones. In addition, the hybrid device manifests fast rise and decay times of 0.1 and 0.23 ms, respectively. These figures-of-merit are among the best values of the recently reported B-Si Schottky photodetectors. We also established that the superior performances are attributed to the strong light absorption of the hybrid structure and increased built-in potential of the graphene/B-Si Schottky junction, which allows efficient separation of photoexcited electron–hole pairs. These findings pave the way toward the rational design of optoelectronic devices through the synergetic effects of 2D materials with 0D and 3D semiconductors.

Solar energy-driven water evaporation lays a solid foundation for important photothermal applications such as sterilization, seawater desalination, and electricity generation. Due to the strong light-matter coupling, broad absorption wavelength range, and prominent quantum confinement effect, layered tin monoselenide (SnSe) holds a great potential to effectively harness solar irradiation and convert it to heat energy. In this study, SnSe is successfully deposited on a centimeter-scale nickel foam using a facile one-step pulsed-laser deposition approach. Importantly, the maximum evaporation rate of SnSe-coated nickel foam (SnSe@NF) reaches 0.85 kg m-2 h-1, which is even 21% larger than that obtained with the commercial super blue coating (0.7 kg m-2 h-1) under the same condition. A systematic analysis reveals that its good photothermal conversion capability is attributed to the synergetic effect of multi-scattering-induced light trapping and the optimal trade-off between light absorption and phonon emission. Finally, the SnSe@NF device is further used for seawater evaporation, demonstrating a comparable evaporation rate (0.8 kg m-2 h-1) to that of fresh water and good stability over many cycles of usage. In summary, the current contribution depicts a facile one-step scenario for the economical and efficient solar-enabled SnSe@NF evaporation devices. More importantly, an in-depth analysis of the photothermal conversion mechanism underneath the layered materials depicts a fundamental paradigm for the design and application of photothermal devices based on them in the future.

With the rapid development of photocatalysis field, photocatalysts have received increasing attention due to their important role in environmental pollution and energy crisis. As a nonmetallic polymeric material, graphite carbon nitride (g-C3N4) is rich in sources and its preparation is simple, and thus has been widely used as a visible-light-responsive photocatalyst. In this review, we have summarized the recent progress related to the design, modification, and construction of g-C3N4 based photocatalysts with excellent photocatalytic performances. First, we have described the basic structure and properties of g-C3N4. Thereafter, we have pointed out that the defects of pristine g-C3N4 and illustrated the general design principles for all of modified strategies. Subsequently, we have discussed various strategies to optimize the photocatalytic properties of g-C3N4 in detail, including constructing Z-scheme heterojunctions based on g-C3N4, morphological controlling, metal deposition, ion doping, dye sensitization, quantum dots modification, and acid treatment. Particularly, we have comprehensively explicated the critical factors governing the performance of the photocatalyst and the enhanced photocatalytic mechanisms of each modification strategy with examples. Finally, we have indicated the challenges of photocatalysis technology using g-C3N4 and proposed the opportunities for further development.

Polycyclic aromatic hydrocarbons (PAHs) in tobacco tar are regarded as a significant threat to human health. PAHs are formed due to the incomplete combustion of organics in tobacco and cigarette paper. Herein, for the first time, we extended the application of CsPbBr3 quantum dots (CsPbBr3) to the photocatalytic degradation of tobacco tar, which was collected from used cigarette filters. To optimize the photoactivity, CsPbBr3 was coupled with Bi2WO6 for the construction of a type-II photocatalyst. The photocatalytic performance of the CsPbBr3/Bi2WO6 composite was evaluated by the degradation rate of PAHs from tobacco tar under simulated solar irradiation. The results revealed that CsPbBr3/Bi2WO6 possesses a large specific surface area, outstanding absorption ability, good light absorption and rapid charge separation. As a result, in addition to good stability, the composite photocatalyst performed remarkably well in degrading PAHs (over 96% were removed in 50 mins of irradiation by AM 1.5 G). This study sheds light on promising novel applications of halide perovskite.

The emergence of a rich variety of layered materials has attracted considerable attention in recent years because of their exciting properties. However, the applications of layered materials in optoelectronic devices are hampered by the low light absorption of monolayers/few layers, the lack of p–n junction, and the challenges for large-scale production. Here, we report a scalable production of β-In2Se3/Si heterojunction arrays using pulsed-laser deposition. Photodetectors based on the as-produced heterojunction array are sensitive to a broadband wavelength from ultraviolet (370 nm) to near-infrared (808 nm), showing a high responsivity (5.9 A/W), a decent current on/off ratio (∼600), and a superior detectivity (4.9 × 1012 jones), simultaneously. These figures-of-merits are among the best values of the reported heterojunction-based photodetectors. In addition, these devices can further enable the detection of weak signals, as successfully demonstrated with weak light sources including a flashlight, lighte...

Because of their great potential for academic investigation and practical application in next-generation optoelectronic devices, ternary layered semiconductors have attracted considerable attention in recent years. Similar to the applications of traditional layered materials, practical applications of ternary layered semiconductor alloys require the synthesis of large-area samples. Here, we report the preparation of centimeter-scale and high-quality Mo0.5W0.5Se2 alloy films on both a rigid SiO2/Si substrate and a flexible polyimide (PI) substrate. Then, photodetectors based on these alloy films are fabricated, which are capable of conducting broad-band photodetection from ultraviolet to near-infrared region (370–808 nm) with high performance. The photodetector on SiO2/Si substrates demonstrates a high responsivity (R) of 77.1 A/W, an outstanding detectivity (D*) of 1.1 × 1012 Jones, and a fast response time of 8.3 ms. These figures-of-merit are much superior to those of the counterparts of binary material...

Layered materials have been found to be promising candidates for next-generation microelectronic and optoelectronic devices due to their unique electrical and optical properties. The p-n junction is an elementary building block for microelectronics and optoelectronics devices. Herein, using the pulsed-laser deposition (PLD) method, we achieve pure In2Se3-based photodetectors and In2Se3/CuInSe2-based photodetectors with a lateral p-n heterojunction. In comparison to that of the pure In2Se3-based photodetector, the photodetectors based on the In2Se3/CuInSe2 heterojunction exhibit a tremendous promotion of photodetection performance and obvious rectifying behavior. The photoresponsivity and external quantum efficiency of the fabricated heterojunction-based device under 532 nm light irradiation are 20.1 A/W and 4698%, respectively. These values are about 7.5 times higher than those of our fabricated pure In2Se3-based devices. We attribute this promotion of photodetection to the suitable band structures of In2Se3 and CuInSe2, which greatly promote the separation of photoexcited electron-hole pairs. This work suggests an effective way to form lateral p-n junctions, opening up a new scenario for designing and constructing high-performance optoelectronic devices.

The fresh water crisis has emerged as one of the most urgent bottlenecks hindering the rapid development of modern industry and society. Solar energy-driven water evaporation represents a potential green and sustainable solution to address this issue. Herein, for the first time, centimeter-scale BiInSe3-coated nickel foam (BiInSe3@NF) as an efficient solar-enabled evaporator was successfully achieved and exploited for solar energy-driven water evaporation. Benefitting from multiple scattering-induced light trapping of the rough substrate, strong light–matter interaction and intermediate band (IB)-induced efficient phonon emission of BiInSe3, the BiInSe3@NF device achieved a high evaporation rate of 0.83 kg m−2 h−1 under 1 sun irradiation, which is 2.5 times that of pure water. These figures-of-merit are superior to recently reported state-of-the-art photothermal conversion materials, such as black titania, plasmonic assembly and carbon black. In addition, superior stability over a period of 60 days was demonstrated. In summary, the current contribution depicts a facile scenario for design, production and application of an economical and efficient solar-enabled BiInSe3@NF evaporator. More importantly, the phonon engineering strategy based on alloying induced IB states can be readily applied to other analogous van der Waals materials and a series of superior vdWM alloys toward photothermal applications can be expected in the near future.

Layered materials have rapidly established themselves as intriguing building blocks for next-generation photodetection platforms in view of their exotic electronic and optical attributes. However, both relatively low mobility and heavier electron effective mass limit layered materials for high-performance applications. Herein, we employed nanodiamonds (NDs) to promote the performance of multilayer In2Se3 photodetectors for the first time. This hybrid NDs-In2Se3 photodetector showed a tremendous promotion of photodetection performance in comparison to pristine In2Se3 ones. This hybrid devices exhibited remarkable detectivity (5.12 × 10(12) jones), fast response speed (less than 16.6 ms), and decent current on/off ratio (∼2285) simultaneously. These parameters are superior to most reported layered materials based photodetectors and even comparable to the state-of-the-art commercial photodetectors. Meanwhile, we attributed this excellent performance to the synergistic effect between NDs and the In2Se3. They can greatly enhance the broad spectrum absorption and promote the injection of photoexcited carrier in NDs to In2Se3. These results actually open up a new scenario for designing and fabricating innovative optoelectronic systems.

Hot carriers, generated via the non-radiative decay of localized surface plasmon, can be utilized in photovoltaic and photocatalytic devices. In recent years, most studies have focused on conventional plasmon materials like Au and Ag. However, they suffer from several drawbacks like low energy of the generated hot carriers and a high charge-carrier recombination rate. To resolve these problems, here, we propose the plasmon resonances in heavily self-doped titanium oxide (TiO1.67) to realize effective hot carrier generation. Since the plasmon resonant energy of TiO1.67 nanoparticles (2.56 eV) is larger than the bandgap (2.15 eV), plasmon resonances through interband transition can realize both the generation and separation of hot carriers and bring a new strategy for visible-light photodegradation. The photodegradation rate for methyl orange was about 0.034 min(-1). More importantly, the combination of plasmonic and catalytic properties makes it feasible to investigate the degradation process of different materials and different structures at the single particle level in situ. By detecting the scattering shift, we demonstrated that the TiO1.67 dimer (Δλ/ΔλRIU = 0.16) possesses a higher photodegradation rate than an individual nanoparticle (Δλ/ΔλRIU = 0.09). We hope this finding may be a beginning, paving the way toward the development of semiconductor plasmonic materials for new applications beyond noble metals.

In this work, a p-type 2D SnS nanofilm containing both laterally and vertically aligned components was successfully deposited on an n-type Si substrate through pulsed-laser deposition. Energy band analysis demonstrates a typical type-II band alignment between SnS and Si, which is beneficial to the separation of photogenerated carriers. The as-fabricated p-SnS/n-Si heterojunction photodetector exhibits multicolor photoresponse from ultraviolet to near-infrared (370–1064 nm). Importantly, the device manifests a high responsivity of 273 A/W, a large external quantum efficiency of 4.2 × 104%, and an outstanding detectivity of 7× 1013 Jones (1 Jones = 1 cm Hz1/2 W–1), which far outperforms state-of-the-art 2D/3D heterojunction photodetectors incorporating either laterally or vertically aligned 2D layered materials (2DLMs). The splendid performance is ascribed to lateral SnS’s dangling-bond-free interface induced efficient carrier separation, vertical SnS’s high-speed carrier transport, and collision ionization...

α-Ag2WO4 (AWO) has been studied extensively due to its H2 evolution and organic pollution degradation ability under the irradiation of UV light. However, the band gap of AWO is theoretically calculated to be 3.55 eV, resulting in its sluggish reaction to visible light. Herein, we demonstrated that, by using the electronic reconstruction of AWO nanorods upon a unique process of laser irradiation in liquid, these nanorods performed good visible-light photocatalytic organics degradation and H2 evolution. Using commercial AWO powders as the starting materials, we achieved the electronic reconstruction of AWO by a recrystallization of the starting powders upon laser irradiation in liquid and synthesized AWO nanorods. Due to the weak bond energy of AWO and the far from thermodynamic equilibrium process created by laser irradiation in liquid, abundant cluster distortions, especially [WO6] cluster distortions, are introduced into the crystal lattice, the defect density increases by a factor of 2.75, and uneven intermediate energy levels are inset into the band gap, resulting in a 0.44 eV decrease of the band gap, which modified the AWO itself by electronic reconstruction to be sensitive to visible light without the addition of others. Further, the first-principles calculation was carried out to clarify the electronic reconstruction of AWO, and the theoretical results confirmed the deduction based on the experimental measurements.

The present study reports the effect of microwave power and microwave heating time on activated carbon adsorption ability. The waste bamboo was used to preparing high surface area activated carbon via microwave heating. The bamboo was carbonized for 2 h at 600°C to be used as the raw material. According to the results, microwave power and microwave heating time had a significant impact on the activating effect. The optimal KOH/C ratio of 4 was identified when microwave power and microwave heating time were 700 W and 15 min, respectively. Under the optimal conditions, surface area was estimated to be 3441 m2/g with pore volume of 2.093 ml/g and the significant proportion of activated carbon was microporous (62.3%). The results of Fourier transform infrared spectroscopy (FTIR) were illustrated that activated carbon surface had abundant functional groups. Additionally the pore structure is characterized using Scanning Electron Microscope (SEM).