Mutabar Shah

Electrical characterization of the organic semiconductor Ag/CuPc/Au Schottky diode

This paper reports on the fabrication and investigation of a surface-type organic semiconductor copper phthalocyanine (CuPc) based diode. A thin film of CuPc of thickness 100 nm was thermally sublimed onto a glass substrate with preliminary deposited metallic electrodes to form a surface-type Ag/CuPc/Au Schottky diode. The current-voltage characteristics were measured at room temperature under dark conditions. The barrier height was calculated as 1.05 eV The values of mobility and conductivity was found to be 1.74 × 10−9 cm2 (V · s) and 5.5 × 10−6 Ω−1 · cm−1, respectively. At low voltages the device showed ohmic conduction and the space charge limited current conduction mechanisms were dominated at higher voltages.

Electrical characterization of the ITO/NiPc/PEDOT: PSS junction diode

This paper reports on the fabrication and characterization of an ITO/NiPc/PEDOT?:?PSS junction diode. A thin film of nickel phthalocyanine (NiPc) was deposited by the thermal vacuum deposition method on indium tin oxide (ITO) used as a substrate. The current?voltage characteristics of the diode were measured at room temperature under dark condition and showed rectifying behaviour. The values of several electrical parameters such as ideality factor, barrier height, conductivity, and series and shunt resistances were calculated.

Organic semiconductor nickel phthalocyanine-based photocapacitive and photoresistive detector

In this study, the photosensitive organic semiconductor nickel phthalocyanine (NiPc) is investigated as a photocapacitive and photoresistive detector. NiPc thin film is grown by vacuum thermal evaporation on an indium tin oxide (ITO)-coated glass substrate. Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is deposited as a top electrode by drop-casting to fabricate the ITO/NiPc/PEDOT:PSS light detector. It has been observed that under the unmodulated filament lamp illumination of up to 9720 lux the capacitance of the detectors increased up to 21, 18 and 4% at a frequency of measuring voltage of 120 Hz, 1 kHz and 10 kHz, respectively, under dark conditions. The change in resistance with the variation in the intensity of light is also investigated. The capacitance and resistance of the light detector decrease with an increase in the frequency. It is assumed that the photocapacitive and photoresistive response of the detector is associated with polarization occurring due to the transfer of photo-generated electrons and holes. The calculated results are in reasonable agreement with the experimental results.

Electrical Characteristics of A1/CNT/NiPc/PEPC/Ag Surface-Type Cell

The blend of nickel phthalocyanine (NiPc) (2 wt. %) poly-N-epoxypropylcarbazole (PEPC), (1 wt. %) and carbon nano-tube (CNT) powder (2 wt. %) in benzole is deposited by drop-casting on glass substrates with pre-deposited metallic electrodes to fabricate Ag/CNT/NiPc/PEPC/A1 surface type cell. It is assumed that the high nonlinearity of the I — V characteristics is related to deep traps in the nano-scale depletion region in NiPc that is observed experimentally. The values of ideality factor and barrier height are determined from the I — V curve and they are found to be 8.4 and 1.05eV, respectively. The values of mobility and conductivity are calculated to be 7.94 × 10−8 cm/Vs and 3.5 × 10−6 Ω−1 cm−1. The values of ideality factor and series resistance are also calculated by using Cheungs functions, which are in good agreement with the values calculated from the I — V curve.

Resistance Pressure Sensor Based on Ag/Cu2O-PEPC-NiPc/Al Composite

This work reports on the fabrication and investigation of pressure sensor based on Ag/Cu2O-PEPC-NiPc/Al composite. The active layer of the composite was deposited by drop-casting of the blend Cu2O-PEPC-NiPc on flexible substrate. The thin film of the blend consist of cuprous oxide (Cu2O) micropowder, (5 wt. %), poly-N-epoxypropylcarbazole (PEPC), (2 wt. %) and nickel phthalocyanine (NiPc) micropowder, (3 wt. %) in benzol (1 ml). The film thickness of the composite is in the range of 20-30 μm. It is found that the fabricated sensor is sensitive to pressure and showed good repeatability. The decrease in resistance of the sensor is observed 10 times by increasing the external uniaxial pressure up to 11.7 kNm-2. The experimentally obtained results are compared with the simulated results and showed reasonable agreement with each other.

Investigation of rectenna for microwave power conversion

This paper presents the fabrication of organic semiconductor (OS) rectifiers and an investigation of rectifying antenna (rectenna) under the effect of microwave power. As a source of microwaves, a patch antenna fed by a generator was used. The rectenna contains a built-in rectifier. The surface-type Ag/NiPc/Au cell, with organic semiconductor nickel phthalocyanine (NiPc) as the active material, was used as a rectenna. The rectifier was fabricated by thermal deposition of Ag, Au and NiPc thin films on thoroughly cleaned glass substrate. The measured I‐V characteristics of the cell showed rectifying behavior. The rectenna was tested at frequency ranges of 8‐16GHz at different intensities of radiation and vertical and horizontal positions of the rectenna’s axes. Under the effect of microwave power at the output of the rectenna, the output dc voltage and current were detected.

Spectroscopic studies of different brands of cigarettes using laser‐induced breakdown spectroscopy

In this work the technique of laser‐induced breakdown spectroscopy (LIBS) has been used for the elemental analysis of cigarettes. For this purpose emission spectra have been measured of eleven different kinds of cigarette brands sold and/or produced in Pakistan. Analysis of the spectral peaks observed shows that Na, Mg, Al, K, Ca, Cr, Fe, Sr and Ba are contained in all brands. Exhibiting the LIBS results, the powerful potential of this method for the identification of the elemental content of cigarettes is demonstrated.

Synthesis, characterization and electrical properties of polypyrrole/V2O5 composites

Polypyrrole (PPy) and its composites with vanadium pentoxide (V2O5) were synthesized in aqueous medium by chemical oxidation polymerization using FeCl3·6H2O as an oxidant. The materials were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffractometry (XRD), thermogravimetry analyzer (TGA), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), UV/visible spectroscopic techniques and LCR-meter. The FT-IR results confirmed the successful synthesis of PPy and PPy/V2O5 composites. The XRD study showed the amorphous and crystalline nature of PPy and PPy/V2O5 composites, respectively. The TGA analysis showed slight increase in the thermal stability of the composites. The SEM data verified the porous nature of PPy and the composites. The UV/visible spectrometry confirmed the doping of PPy in composites. The electrical properties of the materials displayed their semiconducting nature. The resistance of the samples was found to be dependent on temperature and the contents of V2O5 in the composites.

Consistency in Al/CuPc/n-Si Heterojunction Diode Parameters Extracted Using Different Techniques

This paper reports fabrication and characterization of an Al/CuPc/n-Si heterojunction diode. The heterojunction was fabricated by depositing the active organic semiconducting material copper phthalocyanine (CuPc) on the n-Si substrate using the thermal vacuum evaporation technique. Electrical characterization of the fabricated heterojunction was carried out at ambient conditions. Various diode parameters, such as the ideality factor (n), barrier height (