/pdf/physics-of-amorphous-materials-by-s-r-elliott-eyx6ow4nqk.pdf

Physics of amorphous materials by S. R. Elliott

Electrical and photovoltaic properties of FeTPPCl/p-Si heterojunction

The sensing properties of various metallophthalocyanines layered on Quartz Crystal Microbalance (QCM) transducers towards toluene vapor were investigated. Structural and morphological properties of thermally evaporated thin films of substituted and unsubstituted phthalocyanines were firstly characterized by Infrared spectroscopy, X-ray Diffraction and Scanning Electron Microscopy. The sensing characteristics were then determined from QCM responses to toluene at room temperature and correlated to physical and chemical properties of thin films. Effects of molecular composition of phthalocyanine, especially the nature of metal atom in the central cavity and peripheral grafted substituents, on sensor metrological characteristics were established. No significant effect because of change of the central metal atom (Cu, Zn, Fe, Co) in monomeric phthalocyanines was observed on toluene sensitivity. In contrast, strong effects of substituents particularly tert-butyl group at the periphery of the phthalocyanine ring on sensor response were highlighted. The sensing behavior of metallophthalocyanines towards toluene has been interpreted in correlation with the chemical nature of the materials (nature of metal atom and peripheral grafting groups), the physical properties of the sensitive films (structure, morphology and thickness) and the involved molecular interactions forces.

Phthalocyanines based QCM sensors for aromatic hydrocarbons monitoring: Role of metal atoms and substituents on response to toluene

The dark current–voltage of the Au/n+(a-Si:H)/n(SiGe)/p(c-Si)/Ag heterojunction structure have been investigated in order to determinate the electrical conduction mechanisms. The forward current at different temperatures was found to be increased exponentially at low applied voltage $$(V \le 0.4 {\text{V}})$$
 indicating that the conduction mechanism of the diode was controlled by the thermionic emission mechanism. While, at bias voltages higher than 0.5 V, the results obtained show that the carriers conduction was described by the space charge limited current mechanism. The effect of front surface field (FSF) on the photovoltaic parameters of Au/n+ (a-Si:H)/n(SiGe)/p(c-Si) heterojunction solar cell is studied. The experimental results obtained yielded to an improvement of about 50 mV for the open-circuit voltage, 1.1 mA cm−2 for the short-circuit current density, and about 1% for the cell efficiency compared to the conventional cell i.e. without a-Si:H thin layer (FSF).

Electrical transport mechanisms in amorphous silicon/crystalline silicon germanium heterojunction solar cell: impact of passivation layer in conversion efficiency

Fabrication and electrical properties of an organic–inorganic device based on Coumarin 30 dye

Thin films of CoPc of various thickness have been deposited onto glass substrates using thermal evaporation technique at room temperature. The dark electrical resistivity measurements were carried out at different temperature range (298–423 K). An estimation of mean free path () of charge carriers in CoPc thin films and bulk resistivity, was attempted. Measurements of thermoelectric power confirm that CoPc thin films behave as p -type semiconductors. The ac conductivity ( σ ac ) has been investigated in the frequency range (10 2 –10 6  Hz) and temperature range (298–407 K). σ ac is found to be proportional to ω s where s ≈ 0.879 which is frequency and temperature independence. The ac conductivity interpreted by the correlated barrier hopping (CBH) model with centers of intimate valence alternation pairs type with a maximum barrier height, W M ≈ 1.594 eV.

Structural and electrical properties of thermally evaporated cobalt phthalocyanine (CoPc) thin films

http://www.kau.edu.sa/Files/0008706/Researches/62226_33258.pdf

N.M. Khosifan

Papers

Structural and electrical properties of thermally evaporated cobalt phthalocyanine (CoPc) thin films

Electrical transport mechanisms and photovoltaic characterization of cobalt phthalocyanine on silicon heterojunctions

Electronic and photovoltaic properties of Au/pyronine G(Y)/p-GaAs/Au:Zn heterojunction

Fabrication, electrical and photovoltaic characteristics of perylene-66 based diodes (comparative study)