Electrochemical Behavior of Photoactive Thin Solid Films of CdS/Poly (2-(2-Thienyl)furan) as an Inorganic/Organic Interface in Gel Electrolytes

Inorganic/organic interface (I/O/I) Thin solid films made by incorporating cadmium sulfide (CdS) nanoparticles into poly (2-(2-thienyl)furan) (PTF) were subjected to optical and electrochemical investigation in a gel electrolyte. The studies indicate that CdS (n-type) and PTF (p-type) generate consistent photo response. UV-VIS absorption studies suggest that the formed CdS/PTF assembly demonstrates effective absorption across a broad range of photon energies, specifically between approximately 2.2 and 3.3 eV. The fact that PTFs are fluorescent, photoactive polymers promotes more efficient absorption of solar radiation energy and further utilization. Electrochemical studies in gel electrolytes indicate that the occlusion of CdS in PTF under illumination enhances their photoactivities. This is evidenced by larger photocurrents observed in both cathodic and anodic scans compared to those reported for pure PTF. It also indicates that CdS/PTF exhibits type II heterojunction behavior, which improves charge separation and decreases electron-hole recombination. Nyquist plots from electrochemical impedance spectroscopy (EIS) studies reveal a portion of the plot that is controlled by kinetics at high frequencies. Conversely, at low frequencies, Warburg diffusion control is observed. The studied assemblies exhibited stability and resistance to photodegradation, as demonstrated by the regeneration of the same photo response after an extended period of experimentation.