P(HEMA-co-EA) as host polymer for flexible dye-sensitized solar cell (DSSC) electrolyte

Abstract

An electrolyte is the main component of a dye-sensitized solar cell (DSSC) which influences the efficiency of the DSSC. In order to prevent leakage problem and adhesive problem, new solid-state polymer electrolyte proposed rather than using a liquid electrolyte. For this research, new copolymers using 2-hydroxyethyl methacrylate (HEMA) and Ethyl Acrylate (EA) monomers are randomly copolymerized via UV-cure polymerization method with different ratio of each monomer (10,30,50,70,90) towards development as a solid-state electrolyte in flexible DSSC. In this study, the best ratio of the copolymer HEMA-co-EA will be the host polymer for electrolyte in DSSC. The most promising characteristics as a host in polymer electrolytes are due to its smooth cross-sectional surface and lowest glass transition temperature. Therefore, a best ratio of p(HEMA-co-EA) will be stirred with sodium iodide (NaI), Tetrahydro folic acid (THF) and iodine crystal for 24 hours to form a homogenous solution of an electrolyte. This p(HEMA-co-EA) will incorporate with different weight ratios of sodium iodide (NaI). This research reported that after 1500 s only three ratios of new host polymer p(HEMA-co-EA) were successfully copolymerized completely. All three ratio will be characterized by physical appearance, FTIR, DSC and XRD. By naked eyes, only 3 ratios of monomer (50HEMA:50EA, 70HEMA:30EA and 90HEMA:10EA) gave brittle structure which proved the copolymerization process completely success. For FTIR, those three ratios show the breakdown of a double bond at the HEMA monomer structure proved the complete copolymerization process. DSC shows that all three ratio shows the glass transition temperature (Tg) and only 50HEMA:50EA gave melting temperature (Tm) at 192.49°C and XRD confirmed the phase structure and crystallinity of three ratios. All these characterizations show that HEMA and EA monomers can be successfully random copolymerize with a three suitable ratio of each monomer and been used as an electrolyte for flexible DSSC.