Oes the molecular weight of polymers affect the performance of polymer (organic) solar cells

Effects of Molecular Weight on Performance of PSC I. Introduction (a) Thesis ment: molecular weight is one of the main factors that can alter the polymer’s characteristics.
(b) General information: As the world continues seeking renewable energy, solar cells have been proven to have the highest potential, due to its wide abundance. The efficiency of the solar cell is growing due to the vast conducting research. Integrating new materials in designing the solar cells can be one of possible way of enhancing efficiency. The large industry of polymers has introduced conducting polymers that can be used in the solar cells to improve the energy transformation. Physical and chemical properties of polymers may vary based on different factors. &nbsp.
II. First Topic: Understanding Photovoltaic effect
(a) Photovoltaic effect is the formation of electric current or voltage in the material upon exposure to light, and it is the principle that solar cells run on.
(b) Solar cells’ characteristics such as current, voltage, and resistance vary when exposed to light.
(c) Thus, examining the effect of the polymer molecular weight on those characteristics is a necessity, because these are the key factors for developing more efficient cells.
III. Second Topic: Performance of polar solar cells
(a) The performance of polar solar cells relies on a number of factors including the structure of the device, active layer material and interfaces between distinct layers.
(b) Key among these factors is the physical properties of bulk heterojunction, which plays a significant role (Kingsley et al. 22). Components of bulk heterojunction require a broad absorption response in the solar spectrum, which then ensure efficient harvesting of the photons.
(c) In addition, the energy levels donor, which is usually a conjugated polymer, need to match with that of the electron acceptor, which typically is a derivative of fullerene (Intemann et al. 3190). This implies that the donor polymer needs to possess a deep highest occupied molecular orbital, which will ensure a large open circuit voltage (Xiao et al. 75).
IV. Third Topic: Need for improvement
(a) Currently, the recovery of the light is considered to be very low, but it can be improved via changing the properties of the polymers, so the absorption of the light can be more effective.
(b) On this research paper, the effect of the molecular weight will be examined to see if it affects the performance of polymer solar cells. &nbsp.
V. Conclusion
(a) The molecular weight of a conjugated polymer influences the effective conjugated chain (Liu et al. 12165). Therefore, molecular weight makes the electrical and optical properties of the polymers to vary, which improves the performance of polymer solar cells.
(b) Prior to conducting and finalizing the research papers, the writers expect that correlations will be evident between the molecular weight and voltage, light absorbance, and current density of solar cells. These correlations will be further investigated and addressed in depth in the final report.
Works Cited
Intemann, Jeremy J. et al. “Molecular Weight Effect on the Absorption, Charge Carrier Mobility, and Photovoltaic Performance of an Indacenodiselenophene-Based Ladder-Type Polymer.” Chemistry of Materials 25.15 (2013): 3188–3195. ACS Publications. Web. 5 Mar. 2015.
Kingsley, James W. et al. “Molecular Weight Dependent Vertical Composition Profiles of PCDTBT: PC71BM Blends for Organic Photovoltaics.” Scientific Reports 4 (2014): n. pag. www.nature.com. Web. 5 Mar. 2015.
Liu, Chang et al. “Molecular Weight Effect on the Efficiency of Polymer Solar Cells.” ACS Applied Materials &amp. Interfaces 5.22 (2013): 12163–12167. ACS Publications. Web. 5 Mar. 2015.
Xiao, Zeyun et al. “Effect of Molecular Weight on the Properties and Organic Solar Cell Device Performance of a Donor–Acceptor Conjugated Polymer.” Polymer Chemistry (2015): n. pag. pubs.rsc.org. Web. 5 Mar. 2015.