CdS nanoscale photodetectors

Single-Crystalline InGaAs Nanowires for Room-Temperature High-Performance Near-Infrared Photodetectors

InGaAs is an important bandgap-variable ternary semiconductor which has wide applications in electronics and optoelectronics. In this work, single-crystal InGaAs nanowires were synthesized by a chemical vapor deposition method. Photoluminescence measurements indicate the InGaAs nanowires have strong light emission in near-infrared region. For the first time, photodetector based on as-grown InGaAs nanowires was also constructed. It shows good light response over a broad spectral range in infrared region with responsivity of 6.5 × 10³ A W^-1 and external quantum efficiency of 5.04 × 10⁵ %. This photodetector may have potential applications in integrated optoelectronic devices and systems.

Giant UV-sensitivity of ion beam irradiated nanocrystalline CdS thin films

A highly sensitive UV-detector is devised for the first time from ion beam irradiated nanocrystalline CdS thin films. The sensor exhibits improvements in the responsivity, photosensitivity, and efficiency as a function of ion fluence.

Hierarchical CdS Nanowires Based Rigid and Flexible Photodetectors with Ultrahigh Sensitivity

Hierarchical CdS nanowires were synthesized via a facile vapor transport method, which were used to fabricate both rigid and flexible visible-light photodetectors. Studies found that the rigid photodetectors on SiO2/Si substrate showed ultrahigh photo-dark current ratio up to 1.96 × 10(4), several orders of magnitude higher than previously reported CdS nanostructures, as well as high specific detectivity (4.27 × 10(12) Jones), fast response speed and excellent environmental stability. Highly flexible photodetectors were also fabricated on polyimide substrate, which exhibited comparable photoresponse performance as the rigid one. In addition, the as-prepared flexible devices displayed excellent mechanical flexibility, electrical stability and folding endurance. The results indicate that the hierarchical CdS nanowires may be good candidates for nanoscale optoelectronic devices such as high-efficiency photoswitches and highly photosensitive detectors.

High-Performance Fully Nanostructured Photodetector with Single-Crystalline CdS Nanotubes as Active Layer and Very Long Ag Nanowires as Transparent Electrodes

Long and single-crystalline CdS nanotubes (NTs) have been prepared via a physical evaporation process. A metal-semiconductor-metal full-nanostructured photodetector with CdS NTs as active layer and Ag nanowires (NWs) of low resistivity and high transmissivity as electrodes has been fabricated and characterized. The CdS NTs-based photodetectors exhibit high performance, such as lowest dark currents (0.19 nA) and high photoresponse ratio (Ilight/Idark ≈ 4016) (among CdS nanostructure network photodetectors and NTs netwok photodetectors reported so far) and very low operation voltages (0.5 V). The photoconduction mechanism, including the formation of a Schottky barrier at the interface of Ag NW and CdS NTs and the effect of oxygen adsorption process on the Schottky barrier has also been provided in detail based on the studies of CdS NTs photodetector in air and vacuum. Furthermore, CdS NTs photodetector exhibits an enhanced photosensitivity as compared with CdS NWs photodetector. The enhancement in performance is dependent on the larger surface area of NTs adsorbing more oxygen in air and the microcavity structure of NTs with higher light absorption efficiency and external quantum efficiency. It is believed that CdS NTs can potentially be useful in the designs of 1D CdS-based optoelectronic devices and solar cells.

Trap Engineering of CdTe Nanoparticle for High Gain, Fast Response, and Low Noise P3HT:CdTe Nanocomposite Photodetectors

Cd(2+) causes deep traps on the surface of CdTe quantum dots (QDs) often leading to a long response time for a photodetector. Poly(3-hexylthiophene) (P3HT) can be used to selectively passivate the Cd(2+) -related deep traps by forming a Cd-S bond, while maintaining the shallow traps. By tailoring the trap depth of the CdTe QDs, a high gain, fast response, and low noise P3HT:CdTe nanocomposite photodetector is achieved.

Fast and enhanced broadband photoresponse of a ZnO nanowire array/reduced graphene oxide film hybrid photodetector from the visible to the near-infrared range

In the present work, a ZnO nanowire array/reduced graphene oxide film hybrid nanostructure was realized, and the photovoltaic responses from the visible to the near-infrared range were investigated. Compared with the pure ZnO nanowire array and rGO thin film, the hybrid composite exhibited a fast and greatly enhanced broadband photovoltaic response that resulted from the formation of interfacial Schottky junctions between ZnO and rGO.

Single-crystalline In2S3 nanowire-based flexible visible-light photodetectors with an ultra-high photoresponse

With a band gap of 2.28 eV, In2S3 is an excellent candidate for visible-light sensitive photodetectors. By growing single-crystalline In2S3 nanowires via a simple CVD method, we report the fabrication of high-performance single-crystal In2S3 nanowire-based flexible photodetectors. The as-fabricated flexible photodetectors exhibited an ultra-high Ion/Ioff ratio up to 10(6) and a high sensitivity to visible incident light with responsivity and quantum efficiency as high as 7.35 × 10(4) A W(-1) and 2.28 × 10(7)%, respectively. Besides, the flexible photodetectors were demonstrated to possess a robust flexibility and excellent stability. With these favorable merits, In2S3 nanowires are believed to have a promising future in the application of high performance and flexible integrated optoelectronic devices.

LiTaO3 microcubes: the layered structure and the increased Curie temperature

A LiTaO₃ layered micro-nanostructure is fabricated and found to have potential application in the infrared detection field.

CdS : SiO2 nanocomposite as a luminescence-based wide range temperature sensor

A wide range (20–560 K) temperature sensor exhibiting linear behavior in entire range is devised from CdS:SiO₂ nanocomposite with average sensitivity and resolution ≈10⁻² K⁻¹ & 10⁻⁴ K respectively and maximum relative sensitivity ~8.4% K⁻¹ at 120 K.​

A hybrid gel of hypergravity prepared NiO and polyaniline as Li-ion battery anodes

This paper reports a mild preparation of NiO/PANI gel as a Li-ion battery anode, which exhibits enhanced electrochemical performance and cycle stability.

Small molecular amine mediated synthesis of hydrophilic CdS nanorods and their photoelectrochemical water splitting performance

Small molecular amine was selected as the activation agent for elemental sulfur and as a mediator for the formation of hydrophilic CdS nanocrystals with high quality, which exhibit efficient photoelectrochemical properties for water splitting.

Flexible visible-light photodetectors with broad photoresponse based on ZrS3 nanobelt films

Two new flexible visible-light photodetectors based on ZrS3 nanobelts films are fabricated on a polypropylene (PP) film and printing paper, respectively, by an adhesive-tape transfer method, and their light-induced electric properties are investigated in detail. The devices demonstrate a remarkable response to 405 to 780 nm light, a photocurrent that depends on the optical power and light wavelength, and an excellent photoswitching effect and stability. This implies that ZrS3 nanobelts are prospective candidates for high-performance nanoscale optoelectronic devices that may be practically applied in photodetection of visible to near infrared light. The facile fabrication method is extendable to flexible nanodevices with different nanostructures.

Band-selective infrared photodetectors with complete-composition-range InAs(x)P(1-x) alloy nanowires

Band-selective infrared photodetectors (PDs) are constructed with InAs(x)P(1-x) alloy nanowires from the complete composition range (0 ≤ x ≤ 1) achieved by a new growth route combining the vapor-liquid-solid mechanism with an additional ion-exchange process. Increasing the composition x value from 0 to 1 in the PDs allows the peak response wavelength to be gradually tuned from ca. 900 to ca. 2900 nm.

Ultrafast, superhigh gain visible-blind UV detector and optical logic gates based on nonpolar a-axial GaN nanowire

Nonpolar a-axial GaN nanowire (NW) was first used to construct the MSM (metal-semiconductor-metal) symmetrical Schottky contact device for application as visible-blind ultraviolet (UV) detector. Without any surface or composition modifications, the fabricated device demonstrated a superior performance through a combination of its high sensitivity (up to 10(4) A W(-1)) and EQE value (up to 10(5)), as well as ultrafast (<26 ms) response speed, which indicates that a balance between the photocurrent gain and the response speed has been achieved. Based on its excellent photoresponse performance, an optical logic AND gate and OR gate have been demonstrated for performing photo-electronic coupled logic devices by further integrating the fabricated GaN NW detectors, which logically convert optical signals to electrical signals in real time. These results indicate the possibility of using a nonpolar a-axial GaN NW not only as a high performance UV detector, but also as a stable optical logic device, both in light-wave communications and for future memory storage.

Starfish-like Au–CdS hybrids for the highly efficient photocatalytic degradation of organic dyes

A novel starfish-like Au–CdS heterostructures are constructed by a simple self-assembling method with centered Au nanoparticles, and exhibit highly efficient visible light photodegradation of organic dyes.

Effect of solvent and environmental conditions on the structural and optical properties of CdS nanoparticles

Different crystal structures, and tuning of absorption and emission of CdS nanoparticles have been obtained by changing the type of solvent and environmental conditions.