| Summary: | Solid solutions of hexanoyl chitosan/poly(vinyl chloride) (PVC) blends comprising sodium iodide (NaI) were studied. Differential scanning calorimetry results reveal that (i) hexanoyl chitosan and PVC are immiscible and (ii) preferential interaction of NaI with hexanoyl chitosan than PVC. X-ray diffraction results show that the presence of PVC hinders the crystallinity of hexanoyl chitosan and the sample with lower crystallinity exhibits higher conductivity. The maximum conductivities acquired for neat hexanoyl chitosan, PVC, and the blend system are 1.3 × 10−6, 2.9 × 10−8, and 1.5 × 10−5 S cm−1, respectively. The number and mobility of ions were calculated using impedance spectroscopy to elucidate the conductivity variation. The performance of dye-sensitized solar cells (DSSCs) employing hexanoyl chitosan/PVC–NaI electrolytes was investigated with respect to NaI content. With 30 wt% of NaI, DSSC shows an efficiency (η) of 2.93% with short circuit current density (Jsc) of 8.62 mA cm−2 and open circuit voltage (Voc) of 0.58 V. The presence of 4-tert-butylpyridine and guanidinium thiocyanate increases the η to 5.31%, the Jsc to 17.69 mA cm−2, and the Voc to 0.65 V. Improvement of DSSC performance is by passivating the TiO2 surface from recombination. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
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