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Article
Publication date: 9 September 2021

Iyappan Gunasekaran, Govindaraj Rajamanickam, Santhosh Narendiran, Ramasamy Perumalsamy, Kiruthika Ramany and Radha Sankararajan

Various approaches have been made to alter the vibration sensing properties of zinc oxide (ZnO) films to achieve high sensitivity. This paper aims to report the…

Abstract

Purpose

Various approaches have been made to alter the vibration sensing properties of zinc oxide (ZnO) films to achieve high sensitivity. This paper aims to report the experimental study of the fabrication of precursor molar ratio concentration varied ZnO nanostructures grown on rigid substrates using the refresh hydrothermal method. The effect of these fabricated ZnO nanostructures-based vibration sensors was experimentally investigated using a vibration sensing setup.

Design/methodology/approach

ZnO nanostructures have been grown using low temperature assisted refresh hydrothermal method with different precursor molar concentrations 0.025 M (R1), 0.075 M (R2) and 0.125 M (R3). Poly 3,4-ethylenedioxythiophene polystyrene sulfonate, a p-type material is spun coated on the grown ZnO nanostructures. Structural analysis reveals the increased intensity of the (002) plane and better c-axis orientation of the R2 and R3 sample comparatively. Morphological examination shows the changes in the grown nanostructures upon increasing the precursor molar concentration. The optical band gap value decreases from 3.11 eV to 3.08 eV as the precursor molar concentration is increased. Photoconductivity study confirms the formation of a p-n junction with less turn-on voltage for all the fabricated devices. A less internal resistance of 0.37 kΩ was obtained from Nyquist analysis for R2 compared with the other two fabricated samples. Vibration testing experimentation showed an improved output voltage of the R2 sample (2.61 V at 9 Hz resonant frequency and 2.90 V for 1 g acceleration) comparatively. This also gave an increased sensitivity of 4.68 V/g confirming its better performance when compared to the other fabricated two samples.

Findings

Photoconductivity study confirms the formation of a p-n junction with less turn-on voltage for all the fabricated devices. A less internal resistance of 0.37 kΩ was calculated from the Nyquist plot. Vibration testing experimentation proves an increased sensitivity of 4.68 V/g confirming its better performance when compared to the other fabricated two samples.

Originality/value

Vibration testing experimentation proves an increased sensitivity of 4.68 V/g for R2 confirming its better performance when compared to the other fabricated two samples.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 March 1988

G.B. Parravicini, G. Samoggia, B. Morten and M. Prudenziati

A weak change of resistivity caused by visible radiation both for commercial and for model thick‐film (cermet) resistors (TFRs) has been observed and studied in the…

Abstract

A weak change of resistivity caused by visible radiation both for commercial and for model thick‐film (cermet) resistors (TFRs) has been observed and studied in the temperature range 10–380 K. A possible origin of this photoelectric effect in terms of photoexcited electrons emitted from the metallic grain surface into the glassy region is discussed.

Details

Microelectronics International, vol. 5 no. 3
Type: Research Article
ISSN: 1356-5362

Article
Publication date: 5 May 2015

Bo Zhao, Nan Wang and Guohua Jiang

– The purpose of this paper is to arrange zinc oxide (ZnO) nanowires into an appropriate position on electrodes and to research the properties of ZnO nanowires.

Abstract

Purpose

The purpose of this paper is to arrange zinc oxide (ZnO) nanowires into an appropriate position on electrodes and to research the properties of ZnO nanowires.

Design/methodology/approach

In this paper, dielectrophoresis (DEP) was used to fabricate ZnO nanowire devices, and the responses to temperature, ultraviolet (UV) light and breath of the device were studied.

Findings

The number of the bridged nanowires is increased with alternating current voltage. ZnO nanowires demonstrate a good photoconductivity illuminated by 365-nm UV light, and show a stable performance in monitoring unnatural breath of high frequency and low strength.

Originality/value

In this paper, DEP is a promising method for controllable assembly of ZnO nanowires. ZnO nanowires demonstrate a good response to 365-nm UV light and exhaled breath, which show great potential application in UV detector and medical monitor.

Details

Microelectronics International, vol. 32 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 27 June 2020

Belkis Ustamehmetoğlu, Nesrin Köken, Nilgun Kizilcan, Ahmet Akar and Şebnem Tayyar

The purpose of this paper is to produce non-conductive copolymers of N-vinyl carbazole (NVCz) and methyl ethyl ketone formaldehyde resin (MEKFR) by the electroinduced Ce…

Abstract

Purpose

The purpose of this paper is to produce non-conductive copolymers of N-vinyl carbazole (NVCz) and methyl ethyl ketone formaldehyde resin (MEKFR) by the electroinduced Ce (IV) polymerization method and the electrochemical oxidization of the formed copolymer to produce their conductive green form. The non-conductive and conductive copolymers were characterized by using Fourier transform infrared, solid-state conductivity and spectroelectrochemical, chronoamperometric, cyclovoltammetric and electrochemical impedance spectroscopic measurements.

Design/methodology/approach

The chronoamperometric electropolymerization of white, insulator form of the copolymer of NVCz and MEKFR (copolymer 1) on to Pt electrode was carried out and the green coloured film of the MEKFR-ox-NVCz copolymer (copolymer 11) was produced in the doped and conductive form. All reactions were performed in dichloromethane containing 0.1 M BU4NClO4. Copolymer 11 films obtained on the surface of the working electrode were removed and washed in acetonitrile and dried at room temperature before characterization. The results were compared with the copolymer obtained by electrochemical oxidation of MEKF-R and NVCz (copolymer 2).

Findings

The insulating copolymer of NVCz and MEKFR (copolymer 1) was produced by the electroinduced Ce (IV) polymerization method and converted into the conductive form electrochemically on the surface of the Pt electrode (copolymer 11). The polymers were characterized by electrochemical, spectrophotometric and conductivity measurements. The ionization potentials, optical band gap, peak potentials Ep, doping degree and specific capacitance of the copolymer 11 were obtained. The conductivity of the copolymer 11 is lower than the PNVCz and higher than the copolymer obtained by electrochemical oxidation of MEKF-R and NVCz (copolymer 2). The copolymer 11 has a lower onset potential than PNVCz and the copolymer 1 and slightly higher band gap than PNVCz. The capacitive behaviours of the copolymer 11 were very close to PNVCz.

Research limitations/implications

This study focuses on obtaining a green and conductive form of the copolymer of NVCz and MEKFR with the electrochemical method by using a white and insulator form of the same copolymer.

Practical implications

This work provides technical information for the synthesis of conducting copolymer of NVCz and MEKFR.

Social implications

These copolymers may be in the field of PNVCz applications such as photoconductivity and corrosion inhibition.

Originality/value

Electroinduced Ce (IV) MEKFR redox system was applied for the polymerization of NVCz monomer to produce the copolymer 1. The conductive copolymer 11 was synthesized through electrochemical oxidative coupling of the carbazole groups of the copolymer 1.

Details

Pigment & Resin Technology, vol. 50 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 19 June 2019

Kasif Teker, Yassir A. Ali and Ali Uzun

This study aims to investigate photosensing characteristics of SiC and GaN nanowire-based devices through exposure to UV light. The photocurrent transients have been…

115

Abstract

Purpose

This study aims to investigate photosensing characteristics of SiC and GaN nanowire-based devices through exposure to UV light. The photocurrent transients have been modeled to determine rise and decay process time constants. The 1D-semiconductor nanowires can exhibit higher light sensitivity compared to bulk materials because of their large surface area to volume ratio and the quantum size effects.

Design/methodology/approach

Nanowire devices have been fabricated through dielectrophoresis for integrating nanowires onto pre-patterned electrodes (10 nm Ti/ 90 nm Au) with a spacing about 3 µm onto SiO2/Si (doped) substrate. The photocurrent measurements were carried out under room temperature conditions with UV light of 254 nm wavelength.

Findings

SiCNWs yield very short rise and decay time constants of 1.3 and 2.35 s, respectively. This fast response indicates an enhanced surface recombination of photoexcited electron-hole pairs. Conversely, GaNNWs yield longer rise and decay time constants of 10.3 and 15.4 s, respectively. This persistent photocurrent suggests a reduced surface recombination process for the GaNNWs.

Originality/value

High selective UV light sensitivity, small size, very short response time, low power consumption and high efficiency are the most important features of nanowire-based devices for new and superior applications in photodetectors, photovoltaics, optical switches, image sensors and biological and chemical sensing.

Article
Publication date: 14 June 2022

Aminu Muhammad, Sabah M. Mohammad, Zainuriah Hassan, Suvindraj Rajamanickam, Shireen Mohammed Abed and M.G.B. Ashiq

The purpose of this study is to dope silver (Ag) and fluorine (F) in zinc oxide (ZnO) for the enhancement of electrical and optical properties of ZnO, as previous studies…

Abstract

Purpose

The purpose of this study is to dope silver (Ag) and fluorine (F) in zinc oxide (ZnO) for the enhancement of electrical and optical properties of ZnO, as previous studies reported the improvement of these properties using individual doping of F and Ag. In this paper, F and Ag co-doped ZnO nanorods were synthesized using a modified hydrothermal method.

Design/methodology/approach

The hydrothermal method was modified and used for the synthesis of the doped ZnO nanostructures, where stainless autoclave and oven were replaced with the Duran laboratory bottle and water boiler system in the process. The ultraviolet metal-semiconductor-metal photodetector (PD) was fabricated using DC sputtering method.

Findings

Vertically aligned nanorods images were captured from field emission scanning electron microscopy. XPS analysis confirmed greater spin-orbital interaction in the F and Ag co-doped ZnO sample and revealed the presence of F, Ag, Zn and O in the samples, indicating a successful doping process. X-ray diffraction revealed a hexagonal wurtzite structure with enhanced crystal quality upon co-doping. The bandgap decreased from 3.19 to 3.14 eV upon co-doping because of reduced defects density in the sample. Finally, an ultra-violet PD was fabricated with enhanced sensitivity and response times upon co-doping.

Originality/value

The low-cost, less energy-consuming Duran laboratory bottle and water boiler system were used as the substitute of expensive, more energy-consuming stainless autoclave and oven in a hydrothermal method for synthesis of F and Ag co-doped ZnO and subsequent fabrication of PD.

Details

Microelectronics International, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 March 1988

J. Bardeen

This article was part of a commemorative section in Solid State Technology entitled ‘The Transistor—The First Forty Years’, which celebrated the 40th anniversary of the…

Abstract

This article was part of a commemorative section in Solid State Technology entitled ‘The Transistor—The First Forty Years’, which celebrated the 40th anniversary of the December 1987 invention of the transistor at Bell Telephone Laboratories.

Details

Microelectronics International, vol. 5 no. 3
Type: Research Article
ISSN: 1356-5362

Article
Publication date: 25 July 2008

Jiří Franc and Stanislav Nešpůrek

Screen‐printing is an appropriate technique for the manufacture of large‐area position‐sensitive detectors. The purpose of this paper is to present simple methods of paste…

Abstract

Purpose

Screen‐printing is an appropriate technique for the manufacture of large‐area position‐sensitive detectors. The purpose of this paper is to present simple methods of paste preparation and appropriate processing of thick films.

Design/methodology/approach

Active layers of photoconductive cells based on doped CdS0.32Se0.68 were prepared by screen‐printing and sintering at 530°C. A sulfide‐selenide mixture or a mixed crystal material and propylene glycol (PG) was deposited as a paste. PG served as the temporary paste binder. Cadmium chloride was used as a fluxing agent and a donor source. Copper(II) chloride was used as an acceptor source. The effect of the paste composition and sintering time on the resistance and slope of the resistance vs illumination dependence of cells was investigated. These parameters were checked again after eight years of cell storage.

Findings

The cell properties are considerably influenced by the time periods between printing, drying, and sintering. Addition of 2.3 mg Cu2 + and 17 mg Cl per 1 g of mixed crystal CdS0.32Se0.68 enables the preparation of photoconductive cells with the slope higher than 1.2 and a very good long‐term stability of cell parameters.

Research limitations/implications

The effect of the cell parameters' dependence on the paste, age and the time between printing and sintering rendered it impossible to make a more detailed examination after eight‐year storage of samples.

Originality/value

The paper is of value in showing that in the prepared cells exhibit high slopes of resistance‐illumination dependence. The high slope enables detection of laser pulses using only simple filtration of ambient illumination. The changes in photoconductive cell properties after eight‐year storage are presented.

Details

Microelectronics International, vol. 25 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 April 1991

A.A. Buykx, H.M. Wentinck, W. Crans and J.W. Metselaar

For the extraction of transport parameters from Time‐of‐Flight (TOF) measurements a simulation and optimization program was developed that uses the principle of Inverse…

Abstract

For the extraction of transport parameters from Time‐of‐Flight (TOF) measurements a simulation and optimization program was developed that uses the principle of Inverse Modelling. The model describing the physical transport processes in an amorphous device is discussed as well as the implementation of the simulator in the dataprocessor and optimization driver PROFILE. As an example a simulation of TOF measurements at an amorphous p‐i‐n solar cell is shown.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 10 no. 4
Type: Research Article
ISSN: 0332-1649

Article
Publication date: 1 August 2004

H. Niu, L. Lin, X. Bai, Y. Huang and X. Li

A soluble polyschiff base containing triarylamine unit in backbone was synthesised by condensation polymerisation. The hole transport properties of such polyschiff base…

Abstract

A soluble polyschiff base containing triarylamine unit in backbone was synthesised by condensation polymerisation. The hole transport properties of such polyschiff base were studied. The mobility of the hole carrier in the polyschiff base film was also measured and found to be μ=1.68×10−4 cm2/V s by means of time of flight technique. A polymer electroluminescence device was prepared with the polyschiff base used as hole transporting moiety by spin coated.

Details

Pigment & Resin Technology, vol. 33 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

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