Synthesis and Characterization of Mixed-Halide Inorganic-Organic Hybrid CH3NH3PbBr2.5Cl0.5 Perovskite for Photodetector Application

2021 ◽  
Vol 16 (5) ◽  
pp. 707-714
Author(s):  
Yan Chen ◽  
Siwen Tao ◽  
Yaqi Liu ◽  
Xuewei Fu ◽  
Mengyi Pei ◽  
...  
Keyword(s):  
Light Intensity ◽  
Visible Light ◽  
Single Crystal ◽  
Bias Voltage ◽  
Metal Ion ◽  
Low Cost ◽  
Visible Region ◽  
High Sensitivity ◽  
Photocurrent Density ◽  
Organic Hybrid

Inorganic-organic hybrid perovskite (ABX3, A = organic cation, B = metal ion, X = halogen anion) combines the advantages of inorganic and organic materials. However, the properties and performance of mixed-halide CH3NH3PbBr2.5Cl0.5 (MAPbBr2.5Cl0.5) are still poorly understood. In this study, we synthetized MAPbBr2.5Cl0.5 single crystal and studied its structure, optical, thermal stability properties and optoelectronics applications for photodetector device. Compared with those of MAPbCl3, the interplanar distance of (100) crystal plane for MAPbBr2.5Cl0.5 becomes larger and the absorption spectrum of MAPbBr2.5Cl0.5 is extended to the visible region. The band gap of the MAPbBr2.5Cl0.5 single crystal is 2.28 eV. We find the device based on MAPbBr2.5Cl0.5 has high selectivity from 369 to 564 nm. The maximum ▴J (Jon– Joff) under 3.0 V bias voltage is about 1.2 µAcmr-2 at 454 nm visible light with 1 W mr-2 light intensity (1/1000 of the standard sunlight intensity), which proves the device has a high sensitivity. The linear relationship is established between the value of ▴J and light intensity and bias voltage. The fast current intensity transients (Fit) shows that the disappearance period of photocurrent density is 0.3 ms, which indicates the device is rapidly responsive photodetector. The highest value (1.7%) of external quantum efficiency (EQE) and the highest value of detectivities (D) both appear at 480 nm visible light at 4.0 V bias voltage when the irradiation power is 30 W m-2. Therefore, this simple and low-cost photoresponsive device is promising for industrial production of photodetector and photocatalysts device in the future.

Study on Design and Mechanism of a New Invisible Cloak for Visible Light

2014 ◽  
Vol 1035 ◽  
pp. 514-519
Author(s):  
Jing Bo Zhao ◽  
Hong Yao ◽  
Juan Na Jiang
Keyword(s):  
Visible Light ◽  
Total Internal Reflection ◽  
Low Cost ◽  
Visible Region ◽  
Transformation Method ◽  
Macroscopic Object ◽  
Propagation Of Light ◽  
Invisible Cloak ◽  
New Type ◽  
Macroscopic Objects

In order to realize the macroscopic objects invisible in the visible region, according to the law of refraction, total internal reflection law and symmetry reduction transformation method, a new type of visible light stealth cloak was designed. The cloak was prepared using the ordinary homogeneous and isotropic glass materials, which can guide the light around the hidden region, and the direction of propagation of light has not changed. Thus the macroscopic object achieve the perfect stealth. The invisible cloak in air environment for arbitrary polarized visible light have stealth features, easy processing, low cost, has potential application value.

Interface between Nanophotonics and Biotechnology: How the Near-Field Can Boost Proteomics Based on LSPR Nano Sensor

2010 ◽  
Vol 139-141 ◽  
pp. 1554-1557 ◽  
Author(s):  
Xi Xi Huang ◽  
Zhong Cao ◽  
Yong Le Liu ◽  
Yi Min Dai ◽  
Ju Lan Zeng ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Low Cost ◽  
Near Field ◽  
Visible Region ◽  
High Sensitivity ◽  
Nano Particles ◽  
Localized Surface Plasmon ◽  
Bioanalytical Application

An novel optical nano biosensor based on gold capped nano-particles for detecting binding events between ligands and receptor molecules as well as interactions among proteins without use of labels has been presented in this paper. The optical properties of nano-sized gold particles exhibiting pronounced adsorption in the visible region which called as localized surface plasmon resonance (LSPR) have been exploited, whose peak wavelengths depended exquisitely on the refractive index of the surrounding. In comparison with surface plasmon resonance (SPR) technology, the optical nano biosensor possessed high sensitivity, surprisingly low “bulk effect”, ease of preparation, and low-cost polymer based fabrication, which opened a promising bioanalytical application in practice.

Carbon Dot Sensitized Photoanodes for Visible Light Driven Organic Transformations

2019 ◽  
Author(s):  
Francisco Yarur ◽  
John Manioudakis ◽  
Rafik Naccache ◽  
Marek Majewski
Keyword(s):  
Zinc Oxide ◽  
Visible Light ◽  
Carbon Dots ◽  
Low Cost ◽  
Visible Region ◽  
Value Added ◽  
Band Alignment ◽  
Light Illumination ◽  
Carbon Dot ◽  
Electron Transfers

Visible light photosensitization of metal oxides to create heterostructures for the conversion of solar-to-chemical energy is a promising approach to produce solar fuels and other valuable chemicals. Carbon dots have recently been considered as suitable candidates to sensitize wide bandgap metal oxide semiconductors due to their low cost and tunable optical properties. While photocatalytic systems using carbon dots as sensitizers have been reported, transformations involving the production of value-added chemicals as well as the electron transfer mechanisms underpinning photocatalysis within such heterostructures remain underexplored. Here we report the sensitization of zinc oxide nanowires with carbon dots for the α-heteroarylation of 1-phenylpyrrolidine with 2-chlorobenzothiazole under visible light illumination at room temperature. The carbon dots improve the light absorption of the nanowires in the visible region of the spectrum affording the use of white light to drive catalysis. From optical spectroscopy and electrochemistry investigations of the resulting nanohybrid material, the photocatalytic properties are explained by the band alignment at the zinc oxide-carbon dot junction where a series of single-electron transfers creates the necessary potential to oxidize 1-phenylpyrrolidine. The resulting cascade of electron transfers into and from the carbon dots drives the α-heteroarylation to a 97% yield after 24 hrs. <br>

scholarly journals Theoretical insights of codoping to modulate electronic structure of $$\hbox {TiO}_2$$ and $$\hbox {SrTiO}_3$$ for enhanced photocatalytic efficiency

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Manish Kumar ◽  
Pooja Basera ◽  
Shikha Saini ◽  
Saswata Bhattacharya
Keyword(s):  
Electronic Structure ◽  
Visible Light ◽  
Band Gap ◽  
Density Functional ◽  
Low Cost ◽  
Visible Region ◽  
Photocatalytic Efficiency ◽  
Large Shift ◽  
Realistic Condition ◽  
Charged Defects

Abstract $$\hbox {TiO}_2$$ TiO 2 and $$\hbox {SrTiO}_3$$ SrTiO 3 are well known materials in the field of photocatalysis due to their exceptional electronic structure, high chemical stability, non-toxicity and low cost. However, owing to the wide band gap, these can be utilized only in the UV region. Thus, it’s necessary to expand their optical response in visible region by reducing their band gap through doping with metals, nonmetals or the combination of different elements, while retaining intact the photocatalytic efficiency. We report here, the codoping of a metal and a nonmetal in anatase $$\hbox {TiO}_2$$ TiO 2 and $$\hbox {SrTiO}_3$$ SrTiO 3 for efficient photocatalytic water splitting using hybrid density functional theory and ab initio atomistic thermodynamics. The latter ensures to capture the environmental effect to understand thermodynamic stability of the charged defects at a realistic condition. We have observed that the charged defects are stable in addition to neutral defects in anatase $$\hbox {TiO}_2$$ TiO 2 and the codopants act as donor as well as acceptor depending on the nature of doping (p-type or n-type). However, the most stable codopants in $$\hbox {SrTiO}_3$$ SrTiO 3 mostly act as donor. Our results reveal that despite the response in visible light region, the codoping in $$\hbox {TiO}_2$$ TiO 2 and $$\hbox {SrTiO}_3$$ SrTiO 3 cannot always enhance the photocatalytic activity due to either the formation of recombination centers or the large shift in the conduction band minimum or valence band maximum. Amongst various metal-nonmetal combinations, $$\hbox {Mn}_\text {Ti}\hbox {S}_\text {O}$$ Mn Ti S O (i.e. Mn is substituted at Ti site and S is substituted at O site), $$\hbox {S}_\text {O}$$ S O in anatase $$\hbox {TiO}_2$$ TiO 2 and $$\hbox {Mn}_\text {Ti}\hbox {S}_\text {O}$$ Mn Ti S O , $$\hbox {Mn}_\text {Sr}\hbox {N}_\text {O}$$ Mn Sr N O in $$\hbox {SrTiO}_3$$ SrTiO 3 are the most potent candidates to enhance the photocatalytic efficiency of anatase $$\hbox {TiO}_2$$ TiO 2 and $$\hbox {SrTiO}_3$$ SrTiO 3 under visible light irradiation.

scholarly journals Optimization of α-Fe2O3 Nanopillars Diameters for Photoelectrochemical Enhancement of α-Fe2O3-TiO2 Heterojunction

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2019
Author(s):  
Herme G. Baldovi
Keyword(s):  
Fossil Fuels ◽  
Low Cost ◽  
Incident Light ◽  
Visible Region ◽  
Photocurrent Density ◽  
Electron Beam Evaporation ◽  
Green Energy ◽  
Anodized Aluminum ◽  
Separation Processes ◽  
Production Of Hydrogen

Global warming is pushing the world to seek to green energy sources and hydrogen is a good candidate to substitute fossil fuels in the short term. In future, it is expected that production of hydrogen will be carried out through photo-electrocatalysis. In this way, suitable electrodes that acts as photoanode absorbing the incident light are needed to catalyse water splitting reaction. Hematite (α-Fe2O3) is one of the most attractive semiconductors for this purpose since it is a low-cost material and it has a suitable band gap of 2.1 eV, which allows the absorption of the visible region. Although, hematite has drawbacks such as low carrier mobility and short holes diffusion lengths, that here it has been tried to overcome by nanoengineering the material, and by using a semiconductor as a scaffold that enhances charge carrier separation processes in the electrode. In this work, we fabricate ultrathin quasi transparent electrodes composed by highly ordered and self-standing hematite nanopillars of a few tens of nanometers length on FTO and TiO2 supports. Photoanodes were fabricated utilizing electron beam evaporation technique and anodized aluminum oxide templates with well-defined pores diameters. Thus, the activity of the compact layer hematite photoanode is compared with the photoanodes fabricated with nanopillars of controllable diameters (i.e., 90, 260 and 400 nm) to study their influence on charge separation processes. Results indicated that optimal α-Fe2O3 photoanodes performance are obtained when nanopillars reach hundreds of nanometers in diameter, achieving for photoanodes with 400 nm nanopillars onto TiO2 supports the highest photocurrent density values.

scholarly journals Atomically dispersed Pb ionic sites in PbCdSe quantum dot gels enhance room-temperature NO2 sensing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xin Geng ◽  
Shuwei Li ◽  
Lalani Mawella-Vithanage ◽  
Tao Ma ◽  
Mohamed Kilani ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Metal Ion ◽  
High Performance ◽  
Room Temperature ◽  
Limit Of Detection ◽  
Theoretical Calculations ◽  
Low Cost ◽  
High Sensitivity ◽  
Sensor Response ◽  
Response And Recovery

AbstractAtmospheric NO2 is of great concern due to its adverse effects on human health and the environment, motivating research on NO2 detection and remediation. Existing low-cost room-temperature NO2 sensors often suffer from low sensitivity at the ppb level or long recovery times, reflecting the trade-off between sensor response and recovery time. Here, we report an atomically dispersed metal ion strategy to address it. We discover that bimetallic PbCdSe quantum dot (QD) gels containing atomically dispersed Pb ionic sites achieve the optimal combination of strong sensor response and fast recovery, leading to a high-performance room-temperature p-type semiconductor NO2 sensor as characterized by a combination of ultra–low limit of detection, high sensitivity and stability, fast response and recovery. With the help of theoretical calculations, we reveal the high performance of the PbCdSe QD gel arises from the unique tuning effects of Pb ionic sites on NO2 binding at their neighboring Cd sites.

Carbon Dot Sensitized Photoanodes for Visible Light Driven Organic Transformations

2019 ◽  
Author(s):  
Francisco Yarur ◽  
John Manioudakis ◽  
Rafik Naccache ◽  
Marek Majewski
Keyword(s):  
Zinc Oxide ◽  
Visible Light ◽  
Carbon Dots ◽  
Low Cost ◽  
Visible Region ◽  
Value Added ◽  
Band Alignment ◽  
Light Illumination ◽  
Carbon Dot ◽  
Electron Transfers

Visible light photosensitization of metal oxides to create heterostructures for the conversion of solar-to-chemical energy is a promising approach to produce solar fuels and other valuable chemicals. Carbon dots have recently been considered as suitable candidates to sensitize wide bandgap metal oxide semiconductors due to their low cost and tunable optical properties. While photocatalytic systems using carbon dots as sensitizers have been reported, transformations involving the production of value-added chemicals as well as the electron transfer mechanisms underpinning photocatalysis within such heterostructures remain underexplored. Here we report the sensitization of zinc oxide nanowires with carbon dots for the α-heteroarylation of 1-phenylpyrrolidine with 2-chlorobenzothiazole under visible light illumination at room temperature. The carbon dots improve the light absorption of the nanowires in the visible region of the spectrum affording the use of white light to drive catalysis. From optical spectroscopy and electrochemistry investigations of the resulting nanohybrid material, the photocatalytic properties are explained by the band alignment at the zinc oxide-carbon dot junction where a series of single-electron transfers creates the necessary potential to oxidize 1-phenylpyrrolidine. The resulting cascade of electron transfers into and from the carbon dots drives the α-heteroarylation to a 97% yield after 24 hrs. <br>

Nano-surface Monocrystalline BiVO4 Nanoplate Photoanode for Enhanced Photoelectrochemical Performance

2021 ◽  
Author(s):  
Bin Gao ◽  
Tao Wang ◽  
Hairong Xue ◽  
Cheng Jiang ◽  
Lei Sheng ◽  
...  
Keyword(s):  
Single Crystal ◽  
Low Cost ◽  
Photocurrent Density ◽  
Etching Process ◽  
Photoelectrochemical Performance ◽  
Surface Nanostructure

The single-crystal BiVO4 photoanode with surface nanostructure is prepared by a low-cost and simple etching process. As a result, the modified photoanode shows a higher photocurrent density and a lower...

scholarly journals Visible light promoted photocatalytic water oxidation: effect of metal oxide catalyst composition and light intensity

2015 ◽  
Vol 5 (10) ◽  
pp. 4760-4764 ◽  
Author(s):  
Dominic Walsh ◽  
Noelia M. Sanchez-Ballester ◽  
Valeska P. Ting ◽  
Simon R. Hall ◽  
Lui R. Terry ◽  
...  
Keyword(s):  
Transition Metal ◽  
Light Intensity ◽  
Visible Light ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Water Oxidation ◽  
Oxide Catalyst ◽  
Low Cost ◽  
Catalyst Composition ◽  
Oxidation Effect

Simply prepared low-cost nanoparticulate transition metal oxides were used as catalysts in visible light promoted water oxidations. The activity using daylight equivalent light intensities was assessed.

scholarly journals Carbon Dot Sensitized Photoanodes for Visible Light Driven Organic Transformations

2019 ◽  
Author(s):  
Francisco Yarur ◽  
John Manioudakis ◽  
Rafik Naccache ◽  
Marek Majewski
Keyword(s):  
Zinc Oxide ◽  
Visible Light ◽  
Carbon Dots ◽  
Low Cost ◽  
Visible Region ◽  
Value Added ◽  
Band Alignment ◽  
Light Illumination ◽  
Carbon Dot ◽  
Electron Transfers

Visible light photosensitization of metal oxides to create heterostructures for the conversion of solar-to-chemical energy is a promising approach to produce solar fuels and other valuable chemicals. Carbon dots have recently been considered as suitable candidates to sensitize wide bandgap metal oxide semiconductors due to their low cost and tunable optical properties. While photocatalytic systems using carbon dots as sensitizers have been reported, transformations involving the production of value-added chemicals as well as the electron transfer mechanisms underpinning photocatalysis within such heterostructures remain underexplored. Here we report the sensitization of zinc oxide nanowires with carbon dots for the α-heteroarylation of 1-phenylpyrrolidine with 2-chlorobenzothiazole under visible light illumination at room temperature. The carbon dots improve the light absorption of the nanowires in the visible region of the spectrum affording the use of white light to drive catalysis. From optical spectroscopy and electrochemistry investigations of the resulting nanohybrid material, the photocatalytic properties are explained by the band alignment at the zinc oxide-carbon dot junction where a series of single-electron transfers creates the necessary potential to oxidize 1-phenylpyrrolidine. The resulting cascade of electron transfers into and from the carbon dots drives the α-heteroarylation to a 97% yield after 24 hrs. <br>

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