Jamal Uddin

Fabrication, Optimization and Characterization of Natural Dye Sensitized Solar Cell

The dyes extracted from pomegranate and berry fruits were successfully used in the fabrication of natural dye sensitized solar cells (NDSSC). The morphology, porosity, surface roughness, thickness, absorption and emission characteristics of the pomegranate dye sensitized photo-anode were studied using various analytical techniques including FESEM, EDS, TEM, AFM, FTIR, Raman, Fluorescence and Absorption Spectroscopy. Pomegranate dye extract has been shown to contain anthocyanin which is an excellent light harvesting pigment needed for the generation of charge carriers for the production of electricity. The solar cell’s photovoltic performance in terms of efficiency, voltage, and current was tested with a standard illumination of air-mass 1.5 global (AM 1.5 G) having an irradiance of 100 mW/cm2. After optimization of the photo-anode and counter electrode, a photoelectric conversion efficiency (η) of 2%, an open-circuit voltage (Voc) of 0.39 mV, and a short-circuit current density (Isc) of 12.2 mA/cm2 were obtained. Impedance determination showed a relatively low charge-transfer resistance (17.44 Ω) and a long lifetime, signifying a reduction in recombination losses. The relatively enhanced efficiency is attributable in part to the use of a highly concentrated pomegranate dye, graphite counter electrode and TiCl4 treatment of the photo-anode.

Interaction of Sensitizing Dyes with Nanostructured TiO2 Film in Dye-Sensitized Solar Cells Using Terahertz Spectroscopy

The objective of this investigation was to shed light on the nature of interaction of different organic dyes and an inorganic dye, Ruthenium (II) polypyridine complex, with TiO2 nanoparticles. TiO2 is commonly deployed as an efficient energy transfer electrode in dye sensitized solar cells. The efficiency of dye sensitized solar cells is a function of the interaction of a dye with the electrode material such as TiO2. To the best of our knowledge the present study is the first effort in the determination of terahertz absorbance signals, investigation of real-time dye permeation kinetics, and the surface profiling and 3D imaging of dye sensitized TiO2 films. Herein, we report that the terahertz spectra of the natural dye sensitized TiO2 films were distinctively different from that of the inorganic dye with prominent absorption of natural dyes occurring at approximately the same wavelength. It was observed that the permeation of the natural dyes were more uniform through the layers of the mesoporous TiO2 compared to the inorganic dye. Finally, defects and flaws on TiO2 film were easily recognized via surface profiling and 3D imaging of the films. The findings thus offer a new approach in characterization of dye sensitized solar cells.

Dendrimer-based Nanoparticle for Dye Sensitized Solar Cells with Improved Efficiency

Dye sensitized solar cells were fabricated with DyLight680 (DL680) dye and its corresponding europium conjugated dendrimer, DL680-Eu-G5PAMAM, to study the effect of europium on the current and voltage characteristics of the DL680 dye sensitized solar cell. The dye samples were characterized by using Absorption Spectroscopy, Emission Spectroscopy, Fluorescence lifetime and Fourier Transform Infrared measurements. Transmission electron microscopy imaging was carried out on the DL680-Eu-G5PAMAM dye and DL680-Eu-G5PAMAM dye sensitized titanium dioxide nanoparticles to analyze the size of the dye molecules and examine the interaction of the dye with titanium dioxide nanoparticles. The DL680-Eu-G5PAMAM dye sensitized solar cells demonstrated an enhanced solar-to-electric energy conversion of 0.32% under full light illumination (100 mWcm−2, AM 1.5 Global) in comparison with that of DL680 dye sensitized cells which recorded an average solar-to-electric energy conversion of only 0.19%. The improvement of the efficiency could be due to the presence of the europium that enhances the propensity of dye to absorb sunlight.

Terahertz multispectral imaging for the analysis of gold nanoparticles’ size and the number of unit cells in comparison with other techniques

Advances in the controlled assembly of nanoscale building blocks, such as gold and silver nanoscale spheres, and quantum dots (QDs) have resulted in functional devices, such as nano-optoelectronic components, bio-photonics, nanosensors, and novel contrast probes for molecular imaging.1,2 In the assembled structures, the photophysical properties of nanomaterials are a function of the number and the size of the nanomaterials and the distances among them. For instance, the fluorescence lifetime of a quantum dot cluster depends on the number of the QDs, due to the energy transfer between them.3 The surface enhanced Raman spectroscopy (SERS) signal in noble metal nanoparticle arrays depends not only on the properties of the building blocks, but also on the geometric characteristics of the whole array, such as array size. The absorption band of gold nanoparticles is a function of the size and the different fractal structures of the gold nanoparticles and depends on electron-photon relaxation rate.4 Therefore, accurate determination of the size parameter of the nanomaterials is important in order to control the photophysical properties of these nanomaterials. Techniques currently deployed in the determination of particle size include Dynamic Light Scattering,5 Transmission Electron microscope,3 Scanning Electron Microscope7 and Atomic Force Microscope.8 The measured diameter of nanoparticles usually varies depending on the type of instrumentation used for respective measurements. For TEM and SEM, the samples must be small and must remain in high vacuum. Also, for TEM, the samples must be thin enough for electron transparency; as such the sample preparation involves tedious and time consuming steps. AFM imaging is also conducted only on small samples and is strictly a surface imaging technique. In this research, we utilized the terahertz technique as a nondestructive tool capable of non-contact probing and measuring both the size and size distribution of the nanoparticles. Especially, the technique gives one beneficial advantage compared to the AFM, SEM and TEM. It allows us not only to measure the photophysical properties of materials but also to determine the size dimension of some materials9,10 as well as spectroscopic analysis leading to unique identification capabilities.

An Energy Storage and Rapid Charge System Using EDLC for the Solar Light Rail

“The Solar Light Rail” is a proposed power supply method for a 100% renewable energy light rail system. Experiments using a prototype model were carried out in all four seasons in order to verify whether the proposed system can function effectively throughout the day. The primary electric double layer capacitor (EDLC) unit, with a breakdown voltage of 17.5 V and a capacitance of 171.4 F, is charged by solar panels. The secondary EDLC unit which has a breakdown voltage of 15.0 V and a capacitance of 100 F is mounted on the railcar and is charged rapidly by the primary EDLC. The railcar leaves and returns on a straight rail of 9 meters by charged energy, and the secondary EDLC is charged from the primary EDLC again. It was confirmed that the proposed power supply method was effective even in a climate with little or no sunshine, and also that it is necessary to raise the breakdown voltage and capacitance of the primary EDLC to ensure long-term operation after sunset.

Abstract 977: A Strategy to Increase African American Awareness of Health Research

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Evidence shows that there is a shortage of participation in health research trials and blood donations from African American communities. African Americans may be willing to enter into health research studies; however, African Americans are an underrepresented group in health research studies. Although most clinical trial participants are middle-class Caucasian males, due to genetic differences, having a gene pool that is representative of a range of affected individuals will be instrumental in widening our knowledge of various diseases. For instance, there are racial differences in some cancers such as breast, ovarian and prostate cancers. Thus, African American participation will aid in experimental design of health studies in order to target better evaluation, prevention, and treatment of these cancers and other diseases. The purpose of this study is to increase the education and awareness of the Black community because of the need for African American participation in health research studies and blood donations. The three components of this study are to survey, educate, and call to action (SEA). The first component includes administering anonymous surveys to aid in the understanding of current perceptions of health research within the Coppin State University (CSU) community. The second component consists of educational seminars that focus on presenting the history of Blacks and their positive and negative experiences with health research. The third component is a call to action such as having the opportunity to donate blood. The methods and procedures for this study include surveying the CSU community over several questions that focus on a participants interest in participating in a study, knowledge of health research studies in the past such as the Tuskegee Syphilis Study, and ideas on what can be done to increase awareness of health research studies in the CSU community. The study population of 500 students, faculty members, and staff members was able to access surveys via an online website or by completing a form at an on campus location and submitting the form to a sealed box. Preliminary survey results of 59 participants show that 62.7% are interested in donating blood and/or participating in a health research study. In addition, 40.7% were aware of the Tuskegee Syphilis Study. Several participants suggested increasing media avenues such as pamphlets, workshops, and informational commercials in order to better educate the community. In conclusion, the SEA program has made an impact on the CSU community in that several members that have attended the seminars have a better knowledge of previous health research studies and are in a position to make better decisions about donating blood and entering into health research studies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 977.

Abstract B30: Increasing awareness of health research in the African American community

Results from health research studies are important for evaluating, preventing and treating various diseases. African Americans are an underrepresented group in clinical trials and blood donations. Utilizing a gene pool that encompasses a range of affected individuals is instrumental in widening our knowledge of diseases because there are racial differences in some cancers such as those of the breast, ovary, and prostate. Thus, African American participation will aid in experimental design of clinical trials. A lack of trust plays a role in African American underrepresentation. Previous studies suggest researchers can begin to build trust by acknowledging the medical abuses of the past, discussing protection of participants, and explaining the need for minority participation. A major goal of this study is to increase the education and awareness of the black community because of the need for African American participation in health research studies and blood donations. The SEA program is designed to do this by surveying individuals on their current perceptions of health research, educating them on medical abuses of the past, and calling the community to action. The first component includes administering anonymous surveys to aid in the understanding of current perceptions of health research at Coppin State University (CSU) which has a black population of over 95%. The second component consists of educational seminars that focus on presenting the history of blacks and their negative (such as the Tuskegee Syphilis Study) and positive experiences with health research. The third component is a call to action that includes having the opportunity to donate blood or volunteering to educate others. Results show that 29.9% have donated blood and 31.3% are organ donors. 11.6% know of someone in a health study and 43.7% have heard of the Tuskegee Syphilis Study. Concerning interest, the numbers were similar for those that were interested in donating blood and or participating in a health study. The numbers are 54.9% and 53.7%, respectively. 56% said they would participate in a health study if proper monetary compensation was provided. Areas of the second step, education, have also been implemented via professors and other knowledgeable speakers addressing the issues before students. The third area, action, is taking place through regularly scheduled American Red Cross blood drives. In conclusion, the SEA program has made an impact on the CSU community in that several individuals that have attended the seminars and participated in the survey have a better knowledge of previous health research studies and are in a position to make better decisions about donating blood and entering into clinical trials. Future avenues include enlarging the sample size and comparing findings at CSU with other minority and majority communities to obtain an overall view of ways to educate the public about the need for clinical trial participation and blood and organ donation. Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):B30.