{"id":18283,"date":"2022-02-23T09:31:07","date_gmt":"2022-02-23T14:31:07","guid":{"rendered":"https:\/\/textiles.ncsu.edu\/people\/amelsha\/"},"modified":"2024-11-20T15:43:42","modified_gmt":"2024-11-20T20:43:42","slug":"amelsha","status":"publish","type":"person","link":"https:\/\/textiles.ncsu.edu\/people\/amelsha\/","title":{"rendered":"Ahmed El-Shafei"},"content":{"rendered":"

Dr. El-Shafei earned his B.Sc. in Chemistry with honors and M.Sc. in Organic Chemistry both from Mansoura University, Egypt.\u00a0 He joined NC State in August 1998 and earned his Co-Major Ph.D. in Chemistry and Fiber and Polymer Science in December 2002.<\/p>\n

Following his graduation from NC State, he worked as a Post-Doctorate Research Associate and Research Assistant Professor on different projects that span molecular modeling, synthesis, and characterization of dyes and pigments; synthesis, characterization and applications of cationic bleach activators for cotton bleaching; molecular modeling and synthesis of functional dyes for photodynamic therapy; surface chemistry modifications of fibers using non-thermal high-density atmospheric plasma; and X-ray single crystal structure analysis of dyes and pigments..<\/p>\n

Dr. El-Shafei worked as a Teaching Assistant and Assistant Lecturer from 1989 until 1997 and a lecturer from 2005-2006 in the Chemistry Department at Mansoura University, Egypt where he taught organic and polymer chemistry, photochemistry, dye synthesis, dyeing and finishing, physical organic chemistry, mechanism of organic reactions, organic reactions and orbital symmetry (pericyclic reactions).<\/p>\n

Research<\/h3>\n

Research Paradigms in El-Shafei\u2019s Group can be divided into five main thrusts:<\/b><\/p>\n

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  1. Dye-sensitized Solar Cells (DSSCs)<\/b>In the wake of the Fukushima Daiichi and Fukushima Daini Nuclear Plants disasters in Japan in March 2011 coupled with the problems associated with nuclear waste storage and radiation leaks, the world\u2019s needs for clean and safe energy is growing more rapidly than ever before.Solar energy is one of the cleanest and most renewable energy sources we receive on the planet Earth.\u00a0 Yet, we are not taking full advantage of this abundant natural gift. Hence, harnessing the solar energy should be at the forefront of Research and Developments for clean and renewable energy sources in the USA.\u00a0 It has been\u00a0estimated that only 5 minutes of solar irradiation onto the surface of the planet Earth is equivalent to the total energy consumption by humans in one year. Compared to silicon solar cell technology, which is expensive due to its manufacturing cost, Dye-sensitized solar cells (DSSCs) have been attracting more academic and commercial interests because of their superior performance under low lighting conditions, low cost, and independence of incident light angle.\u00a0 For example, DSSCs work from sunrise until sunset even in a rainy and\/or cloudy day more efficiently than silicon PV. They also work more efficiently in ambient light, which makes them a unique class of photovoltaic devices.The principle components of DSCCs, which were invented by Michael Graetzel in 1991, are a sensitizer (a dye or a pigment), an electrolyte (I-\/I3-), and a semiconductor (TiO2) in the nanocrystalline form. The sensitizer is adsorbed on the nanocrystalline TiO2 and is in contact with the electrolyte as shown in Figure 1.\u00a0 The solar-to-electric conversion in DSSCs is mainly dependent on the rate of electron injection from the sensitizer into the semiconductor, which is controlled by the location of the excited state of the dye with respect to the edge of TiO2 conduction band (CB), and the location of the ground state of the sensitizer with respect to the redox potential of the electrolyte.\u00a0 When the cell is exposed to a light source, electrons are excited from the ground state of the sensitizer to its excited state, and depending on the excited state life time and energetic of those excitons, electron injection into the CB of TiO2 may take place.Figure 1:<\/b>\u00a0Schematic representation of the operation and various components of dye-sensitized nanocrystalline semiconductor solar cell.El-Shafei\u2019s group focuses on the molecular modeling, synthesis and photophysics of novel panchromatic sensitizers for highly efficient solid and flexible DSSCs, to advance the science of DSSCs by enhancing the understanding of the interrelationship\u00a0among molecular structures, charge recombinations and electron injections at the interfaces.In our laboratory, DSSCs devices are assembled and characterized using incident-photon-to-current efficiency (IPCE) conversion and total solar-to-electric conversion under the illumination of simulated AM1.5 solar light (100mW\/cm2<\/sup>).Students working in El-Shafei\u2019s group would have the opportunity to learn, gain experience and build unique skills in one or more of the following areas and techniques:\n