scholarly journals A Novel Phototransistor Device with Dual Active Layers Composited of CsPbBr3 and ZnO Quantum Dots

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1215 ◽  
Author(s):  
Xu Zhang ◽  
Qing Li ◽  
Shikai Yan ◽  
Wei Lei ◽  
Jing Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Performance ◽  
Low Cost ◽  
Conducting Layer ◽  
Light Illumination ◽  
High Electron ◽  
Zno Film ◽  
Active Layers ◽  
Zno Qds ◽  
Photodetector Device

Taking advantage of a large light absorption coefficient, long charge carrier diffusion length and low-cost solution processing, all-inorganic halides perovskite CsPbBr3 quantum dots (QDs) are combined with a ZnO QD film to construct a high-performance photodetector. In this work, a novel photodetector device based on transistor structure with dual active layers composed of CsPbBr3 and ZnO film is proposed. In this structure, CsPbBr3 film functions as the light-absorbing layer and ZnO film acts as the conducting layer. Owing to the high electron mobility and hole-blocking nature of the ZnO QDs film, the photo-induced electron-hole pairs can be separated efficiently. As a result, the device exhibits high performance with response of 43.5 A/W, high detection up to 5.02 × 1011 Jones and on/off ratio of 5.6 × 104 under 365 nm light illumination. Compared with the ZnO-only phototransistor (the photodetector with the structure of transistor) the performance of the CsPbBr3 phototransistor showed significant improvement, which is superior to the majority of photodetectors prepared by perovskite. This work demonstrates that the ZnO QDs film can be applied in the photodetector device as a functional conducting layer, and we believe that the hybrid CsPbBr3/ZnO phototransistor would promote the development of low-cost and high-performance photodetectors.

Surface Passivation by Congeneric Quantum Dots for High-Performance and Stable CsPbBr3-Based Photodetectors

2021 ◽  
Author(s):  
Shikai Yan ◽  
Sheng Tang ◽  
Manman Luo ◽  
Lu Xue ◽  
Shilin Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Performance ◽  
Surface Passivation ◽  
Low Cost ◽  
Optoelectronic Properties ◽  
Solution Processing

CsPbBr3-based photodetectors (PDs) have aroused enormous attention owing to their low-cost solution processing, outstanding optoelectronic properties, and remarkable stability. However, their performances remain a big challenge to meet the requirement...

scholarly journals Engineered tunneling layer with enhanced impact ionization for detection improvement in graphene/silicon heterojunction photodetectors

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Yin ◽  
Lian Liu ◽  
Yashu Zang ◽  
Anni Ying ◽  
Wenjie Hui ◽  
...  
Keyword(s):  
High Performance ◽  
Impact Ionization ◽  
Low Cost ◽  
Atomic Layer ◽  
Light Illumination ◽  
Insulation Material ◽  
Defect States ◽  
Uv Illumination ◽  
Layer Deposition ◽  
The Impact

AbstractHere, an engineered tunneling layer enhanced photocurrent multiplication through the impact ionization effect was proposed and experimentally demonstrated on the graphene/silicon heterojunction photodetectors. With considering the suitable band structure of the insulation material and their special defect states, an atomic layer deposition (ALD) prepared wide-bandgap insulating (WBI) layer of AlN was introduced into the interface of graphene/silicon heterojunction. The promoted tunneling process from this designed structure demonstrated that can effectively help the impact ionization with photogain not only for the regular minority carriers from silicon, but also for the novel hot carries from graphene. As a result, significantly enhanced photocurrent as well as simultaneously decreased dark current about one order were accomplished in this graphene/insulation/silicon (GIS) heterojunction devices with the optimized AlN thickness of ~15 nm compared to the conventional graphene/silicon (GS) devices. Specifically, at the reverse bias of −10 V, a 3.96-A W−1 responsivity with the photogain of ~5.8 for the peak response under 850-nm light illumination, and a 1.03-A W−1 responsivity with ∼3.5 photogain under the 365 nm ultraviolet (UV) illumination were realized, which are even remarkably higher than those in GIS devices with either Al2O3 or the commonly employed SiO2 insulation layers. This work demonstrates a universal strategy to fabricate broadband, low-cost and high-performance photo-detecting devices towards the graphene-silicon optoelectronic integration.

A high performance and low cost poly(dibenzothiophene-S,S-dioxide)@TiO2 composite with hydrogen evolution rate up to 51.5 mmol h−1 g−1

2020 ◽  
Vol 8 (35) ◽  
pp. 18292-18301
Author(s):  
Ge Shu ◽  
Ye Wang ◽  
Yuda Li ◽  
Song Zhang ◽  
Jia-Xing Jiang ◽  
...  
Keyword(s):  
Visible Light ◽  
Hydrogen Evolution ◽  
High Performance ◽  
Low Cost ◽  
Evolution Rate ◽  
Light Illumination ◽  
Hydrogen Evolution Rate ◽  
Visible Light Illumination

PDBTSO@TiO2-10 exhibited an extremely high HER of 51.5 mmol h−1 g−1 under visible light illumination.

scholarly journals High-Performance Ultraviolet Light Detection Using Nano-Scale-Fin Isolation AlGaN/GaN Heterostructures with ZnO Nanorods

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 440 ◽  
Author(s):  
Fasihullah Khan ◽  
Waqar Khan ◽  
Sam-Dong Kim
Keyword(s):  
High Performance ◽  
Carrier Transport ◽  
Uv Light ◽  
Zno Nanorods ◽  
Response Speed ◽  
High Electron Mobility Transistor ◽  
Volume Effect ◽  
Light Illumination ◽  
High Electron ◽  
Nano Scale

Owing to their intrinsic wide bandgap properties ZnO and GaN materials are widely used for fabricating passive-type visible-blind ultraviolet (UV) photodetectors (PDs). However, most of these PDs have a very low spectral responsivity R, which is not sufficient for detecting very low-level UV signals. We demonstrate an active type UV PD with a ZnO nanorod (NR) structure for the floating gate of AlGaN/GaN high electron mobility transistor (HEMT), where the AlGaN/GaN epitaxial layers are isolated by the nano-scale fins (NFIs) of two different fin widths (70 and 80 nm). In the dark condition, oxygen adsorbed at the surface of the ZnO NRs generates negative gate potential. Upon UV light illumination, the negative charge on the ZnO NRs is reduced due to desorption of oxygen, and this reversible process controls the source-drain carrier transport property of HEMT based PDs. The NFI PDs of a 70 nm fin width show the highest R of a ~3.2 × 107 A/W at 340 nm wavelength among the solid-state UV PDs reported to date. We also compare the performances of NFI PDs with those of conventional mesa isolation (MI, 40 × 100 µm2). NFI devices show ~100 times enhanced R and on-off current ratio than those of MI devices. Due to the volume effect of the small active region, a much faster response speed (rise-up and fall-off times of 0.21 and 1.05 s) is also obtained from the NFI PDs with a 70 nm fin width upon the UV on-off transient.

High electron mobility ZnO film for high-performance inverted polymer solar cells

2015 ◽  
Vol 106 (16) ◽  
pp. 163902 ◽  
Author(s):  
Peiwen Lv ◽  
Shan-Ci Chen ◽  
Qingdong Zheng ◽  
Feng Huang ◽  
Kai Ding
Keyword(s):  
Solar Cells ◽  
Electron Mobility ◽  
High Performance ◽  
Polymer Solar Cells ◽  
High Electron ◽  
Zno Film ◽  
High Electron Mobility ◽  
Inverted Polymer Solar Cells

scholarly journals Effect of CdS/Mg-Doped CdSe Cosensitized Photoanode on Quantum Dot Solar Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Yingxiang Guan ◽  
Xiaoping Zou ◽  
Sheng He
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
High Performance ◽  
Low Cost ◽  
Energy Conversion Efficiency ◽  
Cdse Qds ◽  
Cdse Quantum Dot ◽  
Sensitized Solar Cells ◽  
Mg Doped

Quantum dots have emerged as a material platform for low-cost high-performance sensitized solar cells. And doping is an effective method to improve the performance of quantum dot sensitized solar cells (QDSSCs). Since Kwak et al. from South Korea proved the incorporation of Mg in the CdSe quantum dots (QDs) in 2007, the Mg-doped CdSe QDs have been thoroughly studied. Here we report a new attempt on CdS/Mg-doped CdSe quantum dot cosensitized solar cells (QDCSSC). We analyzed the performance of CdS/Mg-doped CdSe quantum dot cosensitized solar cells via discussing the different doping concentration of Mg and the different SILAR cycles of CdS. And we studied the mechanism of CdS/Mg-doped CdSe QDs in detail for the reason why the energy conversion efficiency had been promoted. It is a significant instruction on the development of Mg-doped CdSe quantum dot sensitized solar cells (QDSSCs).

scholarly journals Enrichment of Luminescence via Incorporation of Fluxes in La2Zr2O7:Tb3+ Nanophosphors: One Material, Many Possibilities-Latent Fingerprint Visualization, Anti- counterfeiting, Luminescent Flexible Films

2021 ◽  
Author(s):  
D. R. Lavanya ◽  
G. P. Darshan ◽  
J. Malleshappa ◽  
H. B. Premkumar ◽  
S. C. Sharma ◽  
...  
Keyword(s):  
High Performance ◽  
Screen Printing ◽  
Low Cost ◽  
Light Illumination ◽  
Photoluminescence Spectra ◽  
Solution Combustion ◽  
Simple Strategy ◽  
Flexible Films ◽  
Single Material ◽  
Novel Design

Abstract Engineering of single material with multidirectional applications is of crucial for improving the productivity, low cost, flexibility and least power consumption, etc. To achieve these requirements, novel design structures and high performance materials are in urgent need. Lanthanide-doped nanophosphors have greatest strengths and ability in order to tuning its applications in various dimensions. However, nanophosphor applications in latent fingerprints visualization, anti-counterfeiting and luminescent gels/films are still in its infancy. This study demonstrated a simple strategy to enhance the luminescence of Tb3+ doped (1-11 mol %) La2Zr2O7 nanophosphors by conjugating the fluxes via simple solution combustion route. The photoluminescence spectra reveal intense peaks at ~ 491, 546, 587 and 622 nm arises from 5D4◊7FJ (J = 6, 5, 4, 3) transitions of Tb3+ ions, respectively. The highest emission intensity was achieved in the NH4Cl flux assisted nanophosphor as compared to NaBr and NH4F. The colorimetric images of fingerprints visualized using optimized nanophosphor on forensic related surfaces exhibit level –III ridge details, including sweat pores, width of the ridges, bifurcation angle, successive distance between sweat pores, etc. These results are decisive parameters which clearly supports the statement “no two persons have ever been found to have the same fingerprints”. The anti-counterfeiting security ink was formulated using nanophosphor and designed various patterns by simple screen printing and dip pen technology. The encoded information was decrypted only under ultraviolet 254 nm light. All the designed patterns are not just what it looks/feels like and how it works. As a synergetic contribution of enhanced luminescence of the prepared nanophosphor, the fabricated green-emissive films display excellent flexibility, uniformity and transparency in the normal and ultraviolet 254 nm light illumination. Aforementioned results revealed that prepared NH4Cl flux assisted La2Zr2O7: Tb3+(7 mol %) NPs are considered to be best candidate for multi-dimensional applications.

scholarly journals MoS2 Nanosheets Sensitized with Quantum Dots for Room-Temperature Gas Sensors

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jingyao Liu ◽  
Zhixiang Hu ◽  
Yuzhu Zhang ◽  
Hua-Yao Li ◽  
Naibo Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Gas Sensors ◽  
High Performance ◽  
Large Scale ◽  
Room Temperature ◽  
Gas Sensing ◽  
Low Cost ◽  
Surface And Interface ◽  
Sensor Performance ◽  
Semiconductor Gas Sensors

AbstractThe Internet of things for environment monitoring requires high performance with low power-consumption gas sensors which could be easily integrated into large-scale sensor network. While semiconductor gas sensors have many advantages such as excellent sensitivity and low cost, their application is limited by their high operating temperature. Two-dimensional (2D) layered materials, typically molybdenum disulfide (MoS2) nanosheets, are emerging as promising gas-sensing materials candidates owing to their abundant edge sites and high in-plane carrier mobility. This work aims to overcome the sluggish and weak response as well as incomplete recovery of MoS2 gas sensors at room temperature by sensitizing MoS2 nanosheets with PbS quantum dots (QDs). The huge amount of surface dangling bonds of QDs enables them to be ideal receptors for gas molecules. The sensitized MoS2 gas sensor exhibited fast and recoverable response when operated at room temperature, and the limit of NO2 detection was estimated to be 94 ppb. The strategy of sensitizing 2D nanosheets with sensitive QD receptors may enhance receptor and transducer functions as well as the utility factor that determine the sensor performance, offering a powerful new degree of freedom to the surface and interface engineering of semiconductor gas sensors.

Low-Cost UV-IR Dual Band Detector Using Nonporous ZnO Film Sensitized by PbS Quantum Dots

2010 ◽  
Vol 27 (2) ◽  
pp. 027302 ◽  
Author(s):  
Shao Jia-Feng ◽  
A. G. U Perera ◽  
P. V. V Jayaweera ◽  
He De-Yan
Keyword(s):  
Quantum Dots ◽  
Low Cost ◽  
Dual Band ◽  
Zno Film ◽  
Pbs Quantum Dots

Constructing High-performance H3PW12O40/CoS2 Counter Electrodes for Quantum Dots Sensitized Solar Cells by Reducing the Surface Work Function of CoS2

2021 ◽  
Author(s):  
Tingting Zhang ◽  
Qiu Zhang ◽  
Yumeng Wang ◽  
Fengyan Li ◽  
Lin Xu
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Work Function ◽  
High Performance ◽  
Counter Electrode ◽  
Low Cost ◽  
Counter Electrodes ◽  
Surface Work ◽  
Sensitized Solar Cells ◽  
Surface Work Function

The preparation of low cost H3PW12O40 (PW12)/CoS2 complex is used as a counter electrode (CE) to combine with sandwich quantum dots sensitized cells (QDSSCs) composed of TiO2/CdS/CdSe/ZnS photoanode and polysulfide...

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