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Full-Text Articles in Physics

Photovoltaic Effect In Single-Junction Organic Solar Cell Fabricated Using Vanadyl Phthalocyanine Soluble Derivative, Shahino Mah Abdullah Jun 2014

Photovoltaic Effect In Single-Junction Organic Solar Cell Fabricated Using Vanadyl Phthalocyanine Soluble Derivative, Shahino Mah Abdullah

Shahino Mah Abdullah

Purpose: The purpose of this paper is to study the optical and electrical characteristics of a single‐junction solar cell based on a green-color dye Vanadyl 2,9,16, 23-tetraphenoxy-29H, 31H-phthalocyanine (VOPcPhO). The use of soluble vanadyl phthalocyanine derivative makes it very attractive for photovoltaic applications due to its tunable properties and high solubility. Design/methodology/approach: A photoactive layer of VOPcPhO has been sandwiched between indium tin oxide (ITO) and aluminum (Al) electrodes to produce ITO/PEDOT:PSS/VOPcPhO/Al photovoltaic device. The VOPcPhO thin film is deposited by a simple spin coating technique. In order to obtain the optimal thickness for the solar cell device, different thicknesses …


Investigation Of Charge Transport In Organic Polymer Donor/Acceptor Photovolatic Materials, Zubair Ahmad, Shahino Mah Abdullah, Khaulah Sulaiman May 2014

Investigation Of Charge Transport In Organic Polymer Donor/Acceptor Photovolatic Materials, Zubair Ahmad, Shahino Mah Abdullah, Khaulah Sulaiman

Shahino Mah Abdullah

Pi-conjugated organic semiconductors have long been used as either holes or electrons transport materials. Recently ambipolar charge carrier transport in these materials have been reported in many investigations. In this paper, we report on the basis of experimental results that the organic semiconductor (donor/acceptor) materials can be as good electrons transporters as these materials are holes transporters. In our study, the solution-processed unipolar diodes based on organic materials P3HT, VOPCPhO and their blends with PCBM have been fabricated. The I-V characteristics of these diodes have been analyzed in the space charge limited current regime. The values of the electron and …


Nonlocal Diffusion Models: Application To Rapid Solidification Of Binary Mixtures, Sergey Sobolev Jan 2014

Nonlocal Diffusion Models: Application To Rapid Solidification Of Binary Mixtures, Sergey Sobolev

Sergey Sobolev

Various theoretical treatments and models for nonlocal diffusion are briefly reviewed and discussed. The nonlocal effects arise in far from equilibrium processes, which involve extremely fast heat and mass transfer at very small time and length scales. With only diffusive dynamics, the nonlocal models result in a set of transfer equations of parabolic type with an infinite velocity of diffusive disturbances. With the wavelike dynamics, the models lead to a set of transfer equations of hyperbolic type with a finite velocity of diffusive disturbances. Rapid solidification of binary alloys has been used to illustrate the influence of the nonlocal diffusion …


Diffusion-Stress Coupling In Liquid Phase During Rapid Solidification Of Binary Mixtures, Sergey Sobolev Jan 2014

Diffusion-Stress Coupling In Liquid Phase During Rapid Solidification Of Binary Mixtures, Sergey Sobolev

Sergey Sobolev

An analytical model has been developed to describe the diffusion-viscous stress coupling in the liquid phase during rapid solidification of binary mixtures. The model starts with a set of evolution equations for diffusion flux and viscous pressure tensor, based on extended irreversible thermodynamics. It has been demonstrated that the diffusion-stress coupling leads to non-Fickian diffusion effects in the liquid phase. With only diffusive dynamics, the model results in the nonlocal diffusion equations of parabolic type, which imply the transition to complete solute trapping only asymptotically at an infinite interface velocity. With the wavelike dynamics, the model leads to the nonlocal …