Dye‐sensitized solar cells using silicon phthalocyanine photosensitizers with pyridine anchor: Preparation, evaluation of photophysical, electrochemical, and photovoltaic properties

In this study, novel two silicon phthalocyanine photosensitizers ( 3PY‐Si and 4PY‐Si ) containing pyridine groups as an electron‐withdrawing and anchoring group have been prepared and chemically characterized for dye‐sensitized solar cells (DSSCs). Photoelectrochemical and photovoltaic properties of the photosensitizers were evaluated. The new photosensitizers elucidated by spectroscopic and electrochemical techniques. As reported by fluorescence measurements, the silicon phthalocyanine photosensitizers exhibited slightly higher fluorescence quantum yield (Φ F = 0.25) than the unsubstituted zinc phthalocyanine which is favorable for photophysical applications. The DSSC based on complex 3PY‐Si shows the highest power conversion efficiency (PCE) of 0.53% with the J sc , V oc and FF values of 1.205 mA cm −2 , 0.612 V, and 0.72, respectively, in the presence of the coadsorbent. These silicon phthalocyanine photosensitizers with bulky axial pyridine substituents found to be important materials for (DSSCs) since they show strong absorption in the red region and their ligands hamper the stacking of rings. This situation prevented the formation of aggregates with a common tendency to photosensitizers on the TiO 2 surface.