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This paper reports the study of the effect of varying duty cycles on the synthesis of PANI by pulsed electropolymerization method to the performance of PANI as a counter electrode in DSSC. The deposited PANI is in emeraldine salt form, confirmed by FTIR-ATR and Raman spectroscopy. SEM analysis observed that all PANIs has nanofiber morphology. PANI with a 10% duty cycle provides the smallest average diameters X ˉ = 80 n m and lowest film thickness (11.56 μm), lowest RCT (59.00 Ω), lowest RS (40.06 Ω), highest VOC (0.688 V), and highest JSC (9.066 mA cm−2) that lead to the highest performance (η = 2.402%). [ABSTRACT FROM AUTHOR]

It is essential to realize a Raman measurement technique without artifact or fluorescence signals for high-quality and reliable data in a valid molecular-level analysis and interpretation. This requirement applies especially to a molecule with strong fluorescence like porphyrin. Here, the surface of a gold substrate performs better as a DCDR substrate for tetraphenylporphyrin than other surfaces, such as tantalum, indium tin oxide glass, or aluminium. Polarized Raman spectra of tetraphenylporphyrin demonstrated the oriented deposition of porphyrin crystallites on the Au substrate using the drop coating technique. The emission anisotropy suggests that the deposited crystallites are arranged outward radially with the porphyrin ring orientation. The orientation is signed by the NH⋯HN axis that is parallel to the radial vector along the X-axis. Moreover, it also demonstrates high chemical stability after preservation and repeated measurements. The Raman signal on a gold substrate is enhanced more than on other substrates beyond mere preconcentration of analytes or the coffee-ring effect only, which might be due to the contribution of the SERRS effect. This effect will be discussed based on the interactions among localized surface plasmons, vibronic transitions, and Raman active vibrational modes. [ABSTRACT FROM AUTHOR]

Porphyrin has excellent optical properties as required in solar cell applications, for example, high molar extinction coefficient and high quantum efficiency (≈80%). Excellent optical properties make porphyrin a good candidate as a photosensitizer, that is, in dye‐sensitized solar cells (DSSC). Nevertheless, porphyrins exhibit poor charge transfer resulting in poor cell performance. Poor charge transfer in porphyrins is due to the aggregation, low porphyrin adsorption, and weakly bound porphyrins on the TiO2 surface. Anchoring group attached to the porphyrin ring may play an important role to increase both charge transfer and porphyrin adsorption. This study adopts a strategy to increase the electron transfer from porphyrins to TiO2 by applying different anchoring groups. This strategy aims both to reduce the aggregation and to enhance the binding between porphyrin and TiO2 surface. The presence of methyl and carboxylic acid as the anchoring groups in the porphyrin system can increase the electronic coupling between the porphyrin and the TiO2 surface while also hindering the aggregation. Thus, the presence of anchoring groups improves the electron injection efficiency and cell performance. The type and position of the anchoring groups strongly contribute to the electron injection, thus is discussed in detail. [ABSTRACT FROM AUTHOR]