scholarly journals Ultrafast and Stable Planar Photodetector Based on SnS2 Nanosheets/Perovskite Structure

2021 ◽  
Author(s):  
Leyla Shooshtari ◽  
Ali Esfandiar ◽  
Yasin Orooji ◽  
Mahmoud Samadpour ◽  
Reza Rahighi
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Incident Light ◽  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Fast Response ◽  
Band Alignment ◽  
Perovskite Layer ◽  
Pmma Layer

Abstract Two-dimensional (2D) transition metal dichalcogenides (TMDs) are promising candidates of photodetectors where they are commonly grown parallel to the substrate due to their 2D characteristics in micrometer scales from exfoliation of bulk crystals or through high temperature chemical vapor deposition (CVD) methods. In this study, semi-hexagonal vertical nanosheets of SnS2 layered have been fabricated on FTO substrate without using Sn source through CVD method at relatively low temperature (500°C). Due to exceptional band alignment of triple cation lead perovskite with semi- hexagonal SnS2 nanosheets, an improved photodetector has been fabricated. This type of photodetectors fabricated through lithography-free and electrodes metallization free approach with remarkable fast response (20.7µs/31.4µs as rising /falling times), showed high photoresponsivity, external quantum efficiency and detectivity of 1.58 AW-1, 453% and 8.35 ×10 11, respectively under illumination of incident light ith 445nm. The stability of the photodetectors has been studied utilizing a protective PMMA layer on the perovskite layer in 100% humidity. The introduced growth and fabrication process of the planar photodetector, including one/two dimentional interface through the edges/ basal planes of layered materials with perovskite film, paves a way for the large scale, cost-effective and high-performance optoelectronic devices.

scholarly journals Ultrafast and stable planar photodetector based on SnS2 nanosheets/perovskite structure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leyla Shooshtari ◽  
Ali Esfandiar ◽  
Yasin Orooji ◽  
Mahmoud Samadpour ◽  
Reza Rahighi
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Incident Light ◽  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Band Alignment ◽  
Two Dimensional ◽  
Perovskite Layer ◽  
Pmma Layer

AbstractTwo-dimensional (2D) transition metal dichalcogenides are promising candidates of photodetectors where they are commonly grown parallel to the substrate due to their 2D characteristics in micrometer scales from exfoliation of bulk crystals or through high temperature chemical vapor deposition (CVD) methods. In this study, semi-hexagonal vertical nanosheets of SnS2 layered have been fabricated on FTO substrate without using Sn source through CVD method at relatively low temperature (500 °C). Due to exceptional band alignment of triple cation lead perovskite (TCLP) with semi-hexagonal SnS2 nanosheets, an improved photodetector has been fabricated. This type of photodetectors fabricated through lithography-free and electrodes metallization free approach with remarkable fast response (20.7 µs/31.4 µs as rising /falling times), showed high photoresponsivity, external quantum efficiency and detectivity of 1.84 AW−1, 513% and 1.69 × 1011, respectively under illumination of incident light with wavelength of 445 nm. The stability of the photodetectors has been studied utilizing a protective PMMA layer on the perovskite layer in 100% humidity. The introduced growth and fabrication process of the planar photodetector, including one/two dimensional interface through the edges/basal planes of layered materials with perovskite film, paves a way for the large scale, cost-effective and high-performance optoelectronic devices.

Controllable growth of multilayered XSe2 (X=W and Mo) for nonlinear optical and optoelectronic applications

2D Materials ◽  
2021 ◽  
Author(s):  
Kun Ye ◽  
Lixuan Liu ◽  
Liying Chen ◽  
Wenlong Li ◽  
Bochong Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Second Harmonic ◽  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Fast Response ◽  
Peak Position ◽  
Metal Dichalcogenides ◽  
Controllable Growth ◽  
Optoelectronic Applications ◽  
Layered Transition Metal

Abstract The layered transition metal dichalcogenides (TMDs) exhibit the intriguing physical properties and potential application in novel electronic devices. However, controllable growth of multilayer TMDs remains challenging. Herein, large-scale and high-quality multilayer prototype TMDs of W(Mo)Se2 were synthesized via chemical vapor deposition. For Raman and PL measurements, 2H and 3R multilayer WSe2 crystals displayed significant layer-dependent peak position and intensity feature. Besides, different from the oscillatory relationship of SHG intensity for odd-even layer numbers in 2H-stacked multilayer WSe2, the second harmonic generation intensity of 3R-stacked ones parabolically increased with the thickness due to the absence of inversion symmetry. For device application, photodetectors based on WSe2 with increasing thickness exhibited p-type (bilayer), ambipolar (trilayer), and n-type (4 layers) semiconductor behaviors, respectively. Furthermore, photodetectors based on the as-synthesized 3R-stacked WSe2 flakes displayed an excellent responsivity (R) of 7.8×103 mA/W, high specific detectivity (Da*) of 1.7×1014 Jones, outstanding external quantum efficiency (EQE) of 8.6×102 %, and fast response time (τRise=57 ms and τFall=53 ms) under 532 nm illumination with bias voltage of Vds=5 V. Similar results have also been achieved in multilayer MoSe2 crystals. All these findings indicate great potential of 3R-stacked TMDs in two-dimensional optoelectronic applications.

scholarly journals Inexpensive Graphene Oxide Heaters Lithographed by Laser

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1184 ◽  
Author(s):  
Francisco J. Romero ◽  
Almudena Rivadeneyra ◽  
Inmaculada Ortiz-Gomez ◽  
Alfonso Salinas ◽  
Andrés Godoy ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Steady State ◽  
High Performance ◽  
Large Scale ◽  
Spray Deposition ◽  
Cost Effective ◽  
Fast Response ◽  
Stable Steady State ◽  
Steady State Temperature ◽  
High Level

In this paper, we present a simple and inexpensive method for the fabrication of high-performance graphene-based heaters on different large-scale substrates through the laser photothermal reduction of graphene oxide (laser-reduced graphene-oxide, LrGO). This method allows an efficient and localized high level of reduction and therefore a good electrical conductivity of the treated films. The performance of the heaters is studied in terms of steady-state temperature, power consumption, and time response for different substrates and sizes. The results show that the LrGO heaters can achieve stable steady-state temperatures higher than 200 °C when a voltage of 15 V is applied, featuring a time constant of around 4 s and a heat transfer coefficient of ~200 °C cm2/W. These characteristics are compared with other technologies in this field, demonstrating that the fabrication approach described in this work is competitive and promising to fabricate large-scale flexible heaters with a very fast response and high steady-state temperatures in a cost-effective way. This technology can be easily combined with other fabrication methods, such as screen printing or spray-deposition, for the manufacturing of complete sensing systems where the temperature control is required to adjust functionalities or to tune sensitivity or selectivity.

scholarly journals 2D MoS2 Encapsulated Silicon Nanopillar Array with High-Performance Light Trapping Obtained by Direct CVD Process

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 267
Author(s):  
Minyu Bai ◽  
Zhuoman Wang ◽  
Jijie Zhao ◽  
Shuai Wen ◽  
Peiru Zhang ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
High Performance ◽  
Low Cost ◽  
Light Trapping ◽  
Incident Light ◽  
Single Layer ◽  
Chemical Vapor ◽  
Optoelectronic Device ◽  
Planar Silicon ◽  
Shortwave Infrared

Weak absorption remains a vital factor that limits the application of two-dimensional (2D) materials due to the atomic thickness of those materials. In this work, a direct chemical vapor deposition (CVD) process was applied to achieve 2D MoS2 encapsulation onto the silicon nanopillar array substrate (NPAS). Single-layer 2D MoS2 monocrystal sheets were obtained, and the percentage of the encapsulated surface of NPAS was up to 80%. The reflection and transmittance of incident light of our 2D MoS2-encapsulated silicon substrate within visible to shortwave infrared were significantly reduced compared with the counterpart planar silicon substrate, leading to effective light trapping in NPAS. The proposed method provides a method of conformal deposition upon NPAS that combines the advantages of both 2D MoS2 and its substrate. Furthermore, the method is feasible and low-cost, providing a promising process for high-performance optoelectronic device development.

scholarly journals Carbon Nanodots as a Potential Transport Layer for Boosting Performance of All-Inorganic Perovskite Nanocrystals-based Photodetector

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 717
Author(s):  
Hassan Algadi ◽  
Ahmad Umar ◽  
Hasan Albargi ◽  
Turki Alsuwian ◽  
Sotirios Baskoutas
Keyword(s):  
Charge Separation ◽  
High Performance ◽  
Band Alignment ◽  
Transport Layer ◽  
Carbon Nanodots ◽  
Separation Mechanism ◽  
Perovskite Layer ◽  
Inorganic Perovskite ◽  
Highly Efficient ◽  
Efficient Charge

A low-cost and simple drop-casting method was used to fabricate a carbon nanodot (C-dot)/all-inorganic perovskite (CsPbBr3) nanosheet bilayer heterojunction photodetector on a SiO2/Si substrate. The C-dot/perovskite bilayer heterojunction photodetector shows a high performance with a responsivity (R) of 1.09 A/W, almost five times higher than that of a CsPbBr3-based photodetector (0.21 A/W). In addition, the hybrid photodetector exhibits a fast response speed of 1.318/1.342 µs and a highly stable photocurrent of 6.97 µA at 10 V bias voltage. These figures of merits are comparable with, or much better than, most reported perovskite heterojunction photodetectors. UV–Vis absorption and photoluminescent spectra measurements reveal that the C-dot/perovskite bilayer heterojunction has a band gap similar to the pure perovskite layer, confirming that the absorption and emission in the bilayer heterojunction is dominated by the top layer of the perovskite. Moreover, the emission intensity of the C-dot/perovskite bilayer heterojunction is less than that of the pure perovskite layer, indicating that a significant number of charges were extracted by the C-dot layer. The studied band alignment of the C-dots and perovskites in the dark and under emission reveals that the photodetector has a highly efficient charge separation mechanism at the C-dot/perovskite interface, where the recombination rate between photogenerated electrons and holes is significantly reduced. This highly efficient charge separation mechanism is the main reason behind the enhanced performance of the C-dot/perovskite bilayer heterojunction photodetector.

Synthesis of single-crystalline GeS nanoribbons for high sensitivity visible-light photodetectors

2015 ◽  
Vol 3 (31) ◽  
pp. 8074-8079 ◽  
Author(s):  
Changyong Lan ◽  
Chun Li ◽  
Yi Yin ◽  
Huayang Guo ◽  
Shuai Wang
Keyword(s):  
Visible Light ◽  
Vapor Deposition ◽  
High Performance ◽  
Incident Light ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Single Crystalline ◽  
Promising Application ◽  
Photo Detection ◽  
First Time

Single-crystalline GeS nanoribbons were synthesized by chemical vapor deposition for the first time. The nanoribbon photodetectors respond to the entire visible incident light with a response edge at around 750 nm and a high responsivity, indicating their promising application for high performance broadband visible-light photo-detection.

scholarly journals WS(1−x)Sex Nanoparticles Decorated Three-Dimensional Graphene on Nickel Foam: A Robust and Highly Efficient Electrocatalyst for the Hydrogen Evolution Reaction

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 929 ◽  
Author(s):  
Sajjad Hussain ◽  
Kamran Akbar ◽  
Dhanasekaran Vikraman ◽  
Rana Afzal ◽  
Wooseok Song ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Large Scale ◽  
Nickel Foam ◽  
Transition Metal Dichalcogenides ◽  
Three Dimensional ◽  
Cost Effective ◽  
Highly Efficient ◽  
Highly Active ◽  
Earth Abundant

To find an effective alternative to scarce, high-cost noble platinum (Pt) electrocatalyst for hydrogen evolution reaction (HER), researchers are pursuing inexpensive and highly efficient materials as an electrocatalyst for large scale practical application. Layered transition metal dichalcogenides (TMDCs) are promising candidates for durable HER catalysts due to their cost-effective, highly active edges and Earth-abundant elements to replace Pt electrocatalysts. Herein, we design an active, stable earth-abundant TMDCs based catalyst, WS(1−x)Sex nanoparticles-decorated onto a 3D porous graphene/Ni foam. The WS(1−x)Sex/graphene/NF catalyst exhibits fast hydrogen evolution kinetics with a moderate overpotential of ~−93 mV to drive a current density of 10 mA cm−2, a small Tafel slope of ~51 mV dec−1, and a long cycling lifespan more than 20 h in 0.5 M sulfuric acid, which is much better than WS2/NF and WS2/graphene/NF catalysts. Our outcomes enabled a way to utilize the TMDCs decorated graphene and precious-metal-free electrocatalyst as mechanically robust and electrically conductive catalyst materials.

Nanoscale Characterization of WSe2for Opto-electronics Applications

MRS Advances ◽  
2017 ◽  
Vol 2 (60) ◽  
pp. 3715-3720 ◽  
Author(s):  
Nirmal Adhikari ◽  
Avra Bandyopadhyay ◽  
Anupama Kaul
Keyword(s):  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Absorber Layer ◽  
Band Alignment ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Kelvin Probe ◽  
Nanoscale Characterization ◽  
Efficient Charge ◽  
Metal Dichalcogenides

ABSTRACTTwo dimensional (2D) thin transition metal dichalcogenides are being widely investigated for optoelectronics applications. Here, we report on the interfacial study of WSe2with photo-absorber materials for efficient charge transport using Kelvin Probe Force Microscopy (KPFM) for solar cell applications. The WSe2in these experiments was synthesized using Chemical Vapor Deposition (CVD) with a WO3powder and Se pellets as the precursors, where the selenium was placed upstream in an Ar carrier gas within the furnace at a temperature zone of 260-270°C. For the interfacial analysis, nanoscale KPFM measurements show an average surface potential of 125 meV for the CVD synthesized WSe2flakes. KPFM measurements signify that a thin layer of WSe2can be used to suppress back recombination of carriers between the electron transport layer (ETL) and the absorber layer. A proper band alignment between ETL and absorber layer helps to increase the overall device performance, which we will elaborate upon in this work. Capacitance-voltage and capacitance-frequency measurements were measured to study the role of defects.

scholarly journals Superior Pseudocapacitive Storage of a Novel Ni3Si2/NiOOH/Graphene Nanostructure for an All-Solid-State Supercapacitor

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jing Ning ◽  
Maoyang Xia ◽  
Dong Wang ◽  
Xin Feng ◽  
Hong Zhou ◽  
...  
Keyword(s):  
Solid State ◽  
High Performance ◽  
Large Scale ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Specific Area ◽  
High Energy ◽  
Scale Production ◽  
Free Standing

Abstract Recent developments in the synthesis of graphene-based structures focus on continuous improvement of porous nanostructures, doping of thin films, and mechanisms for the construction of three-dimensional architectures. Herein, we synthesize creeper-like Ni3Si2/NiOOH/graphene nanostructures via low-pressure all-solid melting-reconstruction chemical vapor deposition. In a carbon-rich atmosphere, high-energy atoms bombard the Ni and Si surface, and reduce the free energy in the thermodynamic equilibrium of solid Ni–Si particles, considerably catalyzing the growth of Ni–Si nanocrystals. By controlling the carbon source content, a Ni3Si2 single crystal with high crystallinity and good homogeneity is stably synthesized. Electrochemical measurements indicate that the nanostructures exhibit an ultrahigh specific capacity of 835.3 C g−1 (1193.28 F g−1) at 1 A g−1; when integrated as an all-solid-state supercapacitor, it provides a remarkable energy density as high as 25.9 Wh kg−1 at 750 W kg−1, which can be attributed to the free-standing Ni3Si2/graphene skeleton providing a large specific area and NiOOH inhibits insulation on the electrode surface in an alkaline solution, thereby accelerating the electron exchange rate. The growth of the high-performance composite nanostructure is simple and controllable, enabling the large-scale production and application of microenergy storage devices.

scholarly journals Towards High Performance Chemical Vapour Deposition V2O5 Cathodes for Batteries Employing Aqueous Media

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5558
Author(s):  
Dimitra Vernardou ◽  
Charalampos Drosos ◽  
Andreas Kafizas ◽  
Martyn E. Pemble ◽  
Emmanouel Koudoumas
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Large Scale ◽  
Electrode Materials ◽  
Low Cost ◽  
Aqueous Media ◽  
Chemical Vapour ◽  
Cost Effective ◽  
Scale Production ◽  
Environmentally Safe

The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials.

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