Search query: Hydrothermal synthesized.  Photodetector

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abstract: Abstract As one of the few two dimensional intrinsic p type semiconductor materials, tin (II) sulfide (SnS) has gradually emerged in the field of layered metal chalcogenides (LMCs) and has attracted enormous attention due to its superior properties, such as high absorption and low power consumption. In this work, SnS is obtained by a simple, effective and low cost hydrothermal synthesis route. The morphology, phase structure and chemical composition of the obtained SnS are characterized. The results show that the as synthesized SnS has a belt like structure with high purity and crystallinity. The belt length and width are ~15 mm and ~5 mm, respectively. Photodetectors based on such SnS are fabricated, and the photoresponse characteristics are also explored. The photodetectors show excellent and ultrafast photoresponse performance in a broad spectral range in the visible and near infrared regions. The rise and decay time under illumination at the near infrared wavelength of 850 nm laser are short as 1.1 ms and 1.3 ms, respectively. The ultrafast photoresponse performance makes SnS a promising candidate for Vis NIR photodetectors.
author_names: He Tian

Chao Fan

Gangzha Liu

Shuo Yuan

Yonghui Zhang

Mengjun Wang

Erping Li
title: Ultrafast broadband photodetector based on SnS synthesized by hydrothermal method
venue: Applied Surface Science
year: 2019

abstract: Hydrothermal technique is utilized to synthesize 2D/1D heterostructure based on MoS2 (nanosheets)/WS2 (nanorods) for photodetector application. The sensor was fabricated by drop cast technique. X Ray Diffraction (XRD) Fourier Transform Infra red (FTIR) Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) UV Visible (Uv Vis) Raman and X Ray Photoelectron spectroscopy (XPS) were performed to characterize the synthesized sample. The optical sensor based on heterostructure was studied as a function of laser wavelength (lex) 635 nm (red) 785 nm (infra red) and 1064 nm (near infra red) and power of illuminated laser sources. The device exhibits photoresponsivity in a broadband range from the visible to the near infrared (600 1065 nm, yield a photoresponsivity (Rp) 15 mA/W and high specific detectivity (D* 24 x 106 jones at lex 785 nm) The photoresponsive characteristics of MoS2/WS2 heterostructure hold the principle of simple power law.
author_names: Nahid Chaudhary

Manika Khanuja
title: Architectural Design of Photodetector Based on 2D (MoS2 Nanosheets)/1D (WS2 Nanorods) Heterostructure Synthesized by Facile Hydrothermal Method
year: 2019

abstract: In this work, pure and copper mixed oxide PAni nanofiber thin films are successfully synthesized on silicon substrates by hydrothermal method and spin coating technique at room temperature with thickness of about 325 nm. The structural, surface morphological, optical and photoconductivity properties have been investigated. The XRD results showed that PAni films have crystalline nature, CuO and PAni/CuO nanostructure composites are monoclinic polycrystalline structure. The FESEM images of PAni clearly indicate that it has nanofiber like structure, whereas the CuO film has spongelike shape. The surface morphology analysis of PAni/CuO composite shows that nanofiber caped with inorganic material which is CuO is a core shell structure. Optical characterization shows that the direct electronic transition is allowed in the energy gap. The values of energy gap for PAni nanofibers and CuO are 3.98 eV and 5.29 eV respectively. The spectral response of PAni nanofibers, CuO and PAni/CuO composite was studied. The values of responsivity and quantum efficiency of PAni/CuO composite are larger than those for pure PAni nanofibers. One can conclude that with mixing, the sensitivity is higher than that without mixing and is found to be 220 PAni/CuO composite exhibits fast rise time of 0.32 s with full time of 0.41 s, while slow rise time of 0.67 s and 0.38 s was respectively observed for PAni nanofibers and CuO with full time of 3.32 s and 1.19 s.
author_names: M S Ahmed

Mariam Iftikhar

A Bakr Nabeel
title: Photodetector Properties of Polyaniline/CuO Nanostructures Synthesized by Hydrothermal Technique
year: 2019

abstract: In this study, pure Co3O4 nano structure and doping with 4 and6 of Yttrium is successfully synthesized by hydrothermal method.The XRD examination, optical, electrical and photo sensingproperties have been studied for pure and doped Co3O4 thin films.The X ray diffraction (XRD) analysis shows that all films arepolycrystalline in nature, having cubic structure.The optical properties indication that the optical energy gap followsallowed direct electronic transition calculated using Tauc equationand it increases for doped Co3O4. The photo sensing properties ofthin films are studied as a function of time at different wavelengths tofind the sensitivity for these lights.High photo sensitivity doped Co3O4 with 6% of Yttrium, is a118.774% at wavelength 620 nm, while for pure Co3O4 films nosensitivity at the same wavelength. So, higher sensitivity is found fordoping Co3O4 with fast rise and fall times less than 1s.
author_names: Suhad A Hamdan
title: Synthesized pure cobalt oxide nanostructure and doped with yttrium by hydrothermal method for photodetector applications
venue: Iraqi Journal of Physics (IJP)
year: 2019

abstract: Bismuth telluride (Bi2Te3) as a typical of topological insulator, which possesses narrow band gap and exhibited fascinating performance on photodetector filed. In this work, we have fabricated Bi2Te3/graphene heterostructure via a facile one pot hydrothermal method. The as prepared composites used as electrode materials of photoelectrochemical (PEC) type photodetector. From the results of photoelectrochemical tests, we can obviously find Bi2Te3/graphene heterostructure have a remarkable improvement on photoresponse compared to sole Bi2Te3, which effectively demonstrates effective photocarrier generation and transfer at the interface between graphene and Bi2Te3 can enhance the properties of photoresponse. Moreover, owing to the self powered ability of PEC type photodetector, it can work under the bias potential of 0 V and exhibited prominent photoresponse which can reach to 2.2 mA/W. Meanwhile, the photocurrent density of the prepared Bi2Te3/graphene heterostructure based photodetector can almost linearly rise with the increased irradiation power density. Even if the light intensity reduced to 40 mW/cm2, the photocurrent density can also reach 67 mA/cm2, which ensure photodetection ability of the as prepared Bi2Te3/graphene under low light intensity. The excellent performance of Bi2Te3/graphene heterostructure for PEC type photodetector hold the great promising in the field of photoelectric detection.
author_names: Bo Wang

Zongyu Huang

Pinghua Tang

Siwei Luo

Yundan Liu

Jun Li

Xiang Qi
title: One pot synthesized Bi2Te3/graphene for self powered photoelectrochemical type photodetector.
venue: Nanotechnology
year: 2019

abstract: The present low yielding growth techniques of semiconducting 2H phase molybdenum disulfide (MoS2) hamper its widespread applications. In this article, we report a novel hydrothermal chemical approach to synthesize micron sized few layer 2H MoS2 on a large scale. Sodium molybdate and ammonium thiocyanate have been used as precursors to obtain template free 2H MoS2 in solution. Detailed microscopic and spectroscopic characterizations reveal that the bottom up synthesized few layer MoS2 flakes are highly crystalline having the hexagonal 2H phase. Photodetector devices comprising a p type silicon (p Si)/n MoS2 heterostructure have been fabricated for the first time using solution processed 2H MoS2 synthesized by the bottom up approach. The heterojunction diode exhibits a high rectification ratio >103) with broad band photoresponse over the visible range. Because of the visible light photoresponse, as synthesized MoS2 along with reduced graphene oxide (MoS2 RGO hybrids) have been utilized to study the potential of this two dimensional (2D) heterostructure for visible light driven photocatalytic Rhodamine B dye degradation. This study demonstrates the potential of solution processed MoS2 for integration with silicon and growth of 2D heterostructures for visible light induced multifunctional applications.
author_names: Anupam Midya

Arup Ghorai

Subhrajit Mukherjee

Rishi Maiti

Samit Kumar Ray
title: Hydrothermal growth of few layer 2H MoS2 for heterojunction photodetector and visible light induced photocatalytic applications
year: 2016

abstract: Dumbbell and flower like ZnO nano crystals were grown via hydrothermal process. The as prepared dumbbells, with length of 0.8 10 um and edge length of 0.3 0.8 um possess a hexagonal structure, while flowers with lengths ranging from 1 6 um with hexagonal structure have been synthesized. The effect of temperature, solution concentration and growth time on the size and shapes of the ZnO nanostructures has been studied using Field emission scanning electron microscope (FESEM) and X ray diffractometer (XRD) Further the optical properties of nanostructures were investigated by Photoluminescence (PL) spectroscopy, which shows emission in UV and visible regions. From Diffused reflectance spectroscopic analysis (DRA) it was observed that ZnO nanodumbbells and nanoflowers have a direct band gap of 3.27 eV and 3.25 eV respectively. The I V plot showed dependence of current values under dark and illumination over the annealing temperature during the growth stage. Thus we report a control over the shape and dimension of nanostructures by varying various parameters having implications for (opto)electronic devices.
author_names: Tejendra Dixit

Anubha Bilgaiyan

I A Palani

Vipul Singh
title: Influence of Parametric Variations on Hydrothermal Growth of ZnO Nanostructures for Hybrid Polymer/ZnO Based Photodetector.
venue: Journal of nanoscience and nanotechnology
year: 2016

abstract: Abstract The photoresponse properties of Bi 2 Se 3 nanosheets prepared by a simple hydrothermal intercalation and exfoliation route are studied. Photoelectrochemical results indicate that the as prepared Bi 2 Se 3 nanosheets devices have excellent sensitivity, high speed and good reproducibility as a photodetector, which are superior to the bulk Bi 2 Se 3 Especially, the response time, responsivity, and external quantum efficiency are found to be about 0.7 s, 20.48 mA/W, and 8.36 e 0 respectively. It is proposed that the two dimensional nanostructure of Bi 2 Se 3 can be effectively used in high performance nanoscale photodetectors.
author_names: Chengjie Zang

Xiang Qi

Long Ren

Guolin Hao

Yundan Liu

Jun Li

Jianxin Zhong
title: Photoresponse properties of ultrathin Bi2Se3 nanosheets synthesized by hydrothermal intercalation and exfoliation route
year: 2014

abstract: We have successfully synthesized Fe doped ZnO nanorods by a new and simple method in which the adopted approach is by using ammonia as a continuous source of OH for hydrolysis instead of hexamethylenetetramine (HMT) The energy dispersive X ray (EDX) spectra revealed that the Fe peaks were presented in the grown Fe doped ZnO nanorods samples and the X ray photoelectron spectroscopy (XPS) results suggested that Fe3+ is incorporated into the ZnO lattice. Structural characterization indicated that the Fe doped ZnO nanorods grow along the c axis with a hexagonal wurtzite structure and have single crystalline nature without any secondary phases or clusters of FeO or Fe3O4 observed in the samples. The Fe doped ZnO nanorods showed room temperature (300 K) ferromagnetic magnetization versus field (M H) hysteresis and the magnetization increases from 2.5 uemu to 9.1 uemu for Zn0.99Fe0.01O and Zn0.95Fe0.05O, respectively. Moreover, the fabricated Au/Fe doped ZnO Schottky diode based UV photodetector achieved 2.33 A/W of responsivity and 5 s of time response. Compared to other Au/ZnO nanorods Schottky devices, the presented responsivity is an improvement by a factor of 3.9.
author_names: Chan Oeurn Chey

Ansar Masood

Anastasia V Riazanova

Xianjie Liu

K Venkata Rao

Omer Nur

Magnus Willander
title: Synthesis of fe doped zno nanorods by rapid mixing hydrothermal method and its application for high performance UV photodetector
year: 2014

abstract: Titanium dioxide (TiO2) has drawn a potential research interest for ultraviolent (UV) photodetector (PD) applications because of its tunable bandgap in UV absorption region, low absorption coefficient in visible region, n type semiconducting property, and excellent chemical stabilities. In this study, attempts were made to explore the performances of TiO2 nanostructures such as nanotubes (NTs) and nanorods (NRs) based UV PDs embedded with 23 nm plasmonic silver (Ag) nanoparticles (NPs) which offer the local surface plasmonic resonance or near field enhancement. The vertical TiO2 NTs and NRs with high uniformity and height of 1 um were successfully synthesized using simple and low cost electrochemical anodization and hydrothermal growth techniques, respectively onto Ti substrates. From the x ray diffraction analysis, it was ascertained that the anatase phase has been formed for NTs, whereas the rutile phase dominated the NRs. All these nanostructures were characterized by various material characterization techniques such as field emission scanning electron microscopy, x ray photoelectron spectroscopy, UV vis NIR and Raman spectroscopy to investigate their surface and structural morphologies and absorption spectra. Efforts were put to fabricate Ag/ (with or without Ag NPs) TiO2 nanostructures/ Ti based UV PDs, where Ag has been utilized as top electrode and Ti served the purpose for bottom electrode. The electrical characteristics such as current voltage, responsivity, detectivity, external quantum efficiency, rise and decay times were systematically investigated under 365 nm UV light radiance. Among all the UV PDs, TiO2 NTs anchored with the Ag NPs offer better photocurrent, responsivity (1.37 AW 1) detectivity (5.18 x 1010 Jones) external quantum efficiency (465.42% rise (0.43 s) and decay (0.70 s) times. In order to have better insight on the device operational principle, a band diagram was proposed and it was realized that desorption of oxygen ions, increment of free electron carriers, and localized surface plasmonic effect were responsible for obtaining improved photoresponse.
author_names: P Joshna

Arnab Hazra

Karumbaiah N Chappanda

Prasant Kumar Pattnaik

Souvik Kundu
title: Fast response of UV photodetector based on Ag nanoparticles embedded uniform TiO2 nanotubes array
venue: Semiconductor Science and Technology
year: 2019