INDIA :
his is the first part of the series called-Scientist Says-where we would be presenting research works of young scientists in various fields.
Khadija Kanwal Khanum has done her PhD and Postdoctoral fellow from Indian Institute of Science (IISc), Bengaluru, India (2010-2018). Presently, she is a postdoctoral fellow at the University of Waterloo, Waterloo, Canada. She shares with Rashida Bakait of India Tomorrow, her significant studies and research on “Solar Cells’’.
Q. What was the topic of your research at IISc and a brief explanation about the same?
Ans. The broad topic of my doctoral and postdoctoral research at Indian Institute of science, Bengaluru, was fabrication, characterization and analyses of organic and hybrid photovoltaics (solar cells) to enhance the solar cell’s device performances. Specifically, the title of my doctoral thesis was “Morphological Architecturing of electroactive materials in organic electronics”. In this research, organic and organic-inorganic (hybrid) semiconductor/electroactive materials are used, instead of inorganic semiconductor materials/silicon to fabricate the solar cells. The organic and hybrid materials compare to the inorganic materials/ silicon counterparts are lab synthesized materials with ability to easily tailor the band gap (as semiconductors), and require less energy during their solar cell fabrication hence cost-effective. However, these organic and hybrid solar cells have till now reported, less power conversion efficiency, PCE (>25%) and are less stable in environment and therefore, require extensive research before their wide commercialization.
Q. What was the aim behind your research?
Ans. In this research, a different fabrication procedure was used called Electro-spinning, in order to enhance the light absorption as well as increase the charge (electron-hole) separation in the solar device, thereby increasing its PCE.
Q. What kind of new aspects were highlighted in your research?
Ans. The highlighting parts of the research were 1).The active layer of the solar cell which is generally in a thin film form was modified to fiber and various other forms such as network (Khanum and Ramamurthy, 2016), photonic (Khanum et al., 2017), two and three-dimensional triangles (Khanum and Ramamurthy, 2018) and spike-spheres (Khanum et al., 2015) structures using electrospinning/ electrospraying method. 2). The modified active layers assisted in improving the solar devices’ light absorption by 19 – 31% and PCE by 23 – 68%.
Q. When did you begin and complete your research?
Ans. I joined IISc as a doctoral student, in Aug 2010 and subsequently took few advance and elective courses in polymer science and technology, nanotechnology, vacuum systems, sensors and material characterization for one year, in order to gain knowledge and understanding of the above subjects, which helped me in my research. I started my research sometime around June 2011, submitted my doctoral thesis in July 2015, defended the thesis in July 2016, and continued the research as research associate and postdoctoral fellow till Mar 2018.
Q. What kind of challenges you faced?
Ans. Since organic electroactive materials used in this research are conjugated small molecules and polymers possessing, low molecular weight than conventional polymers hence, fiber formation using electrospinning was difficult. Therefore, lot of optimization of the electrospinning process parameters and modifications of the organic and hybrid materials used such as; preparation time, concentration and solvent used had to be meticulously carried out, during solar cells fabrication. Additionally, maintaining inert atmosphere both, during fabrication and characterization of solar cells required lot of patience and cautions, making this study iterative and time-consuming. For instance, it took almost two years in this study, to obtain first few successful solar cell devices.
Q. Any scholarships or awards for research?
Ans. For my PhD and postdoctoral research, major part of the funding was received as scholarship from Ministry of Human Resource Development (MHRD) and Institute (IISC) research associate fund while during last 15 months; I received scholarship from my Ph.D and Postdoctoral advisor from his project grant. I received few awards and grants to present the research work in various international conferences; Manish Narayan memorial award from Department of Materials Engineering, IISc in 2014, Indian Institute of Science support and grant in 2014 and 2015, Department of Science and Technology (DST) young scientist in 2016 and International Workshop on Advanced Materials (IWAM), Ras Al Khaimah, UAE travel grant in 2016 and 2018.
Q. How do you think your research would be beneficial to industry/ society?
Ans. Energy from sun that strikes the earth in a year is enormous, precisely equals to 3 x 1024 J, or about 10, 000 times more than current global energy consumption. Covering 0.1% of the earth’s surface with 10% efficiency solar cells would suffice the energy demand of the whole world (Siddiki et al., 2010). Therefore, my research of improving the light absorption and PCE of organic and hybrid solar cells through morphological architecturing would be one of the smart tools that can be used to trap and utilize the renewable and sustainable energy resource (solar energy).
Q. What was the conclusion of your research?
Ans. In conclusion, in this research `Electrospinning Processing Technique’ is evaluated as one of the novel processing techniques for morphology patterning, leading to improvements in structural, optical and opto-electrical properties of organic and hybrid electroactive materials. Further these electroactive materials based on morphological patterning were also evaluated as organic solar cells with 19 – 31% increment in light/ optical absorption and 23 – 68% enhancement in PCE (Khanum and Ramamurthy, 2016; Khanum et al., 2017; Khanum and Ramamurthy, 2018).
Q. How do you think your research can be carried forward?
Ans. The research could be extended in studying the life stability and field performance of these solar cells. The research could also be extended by using electrospinning processing technique to generate more morphological structures than studied in this research (mentioned in Q3’s reply) and evaluate their properties in the field of photovoltaics/solar devices. The already generated morphological structures such as network, photonic, two and three-dimensional triangles and spike-spheres structures are made up of organic electroactive materials and can be explored in the field of sensors and medical applications as in drug delivery and as tissue scaffolds, therefore the feasibility in these areas could also be one of the future direction.
Q. Can you brief us about your current research?
Ans. Yes, my research at University of Waterloo, Canada is on nanocomposites materials employed in power industry. As the World’s energy demand seems to be all time high and increasing, the focus of research is now more on renewable and sustainable energy. The power industry needless to mention, acts as a bridge between all types of energy generation and the consumers. In my present work, the importance of nanocomposites materials and its processing with respect to power industry are researched. Nanocomposites are remarkable class of materials, consisting of various types of nanofillers which act as reinforcement in the matrix and thus enhance the desired properties. These nanomaterials have to be dispersed homogeneously in the matrix to gain optimized effects and therefore require special processing tools. Therefore, in this research, processing of various polymer nanocomposites of silicone filled with Silica and Alumina fillers are studied.
Q. Apart from your main research topic, would you like to list any other work you collaborated and worked on?
Ans. Yes, besides fabrication, characterization and analyses of organic and hybrid solar cells, I collaborated and worked on few other interesting topics such as– Developed silk and melanin nanofibers mats for the bio-application such as scaffolds for tissue engineering, evaluated the effectiveness of non-water based cleaning mechanisms for photovoltaic (PV) systems. Studied the influence of dust density and composition on performance of PV systems using Infrared (IR) radiation and assessed magnetic materials and their integration in fibre reinforced polymer composites for structural applications.
source: http://www.indiatomorrow.net / India Tomorrow / Home> Education / by Rashida Bakhait, India Tomorrow / March 17th, 2021