Dye-sensitized solar cells (DSSCs) suffer from efficiency limitations due to interfacial charge recombination at the TiO₂/dye/electrolyte interface. In this study, aminopropyltrimethoxysilane (APS) was introduced onto nanoporous TiO₂ photoelectrodes via a dip-coating process with controlled coating times to investigate the effect of silanization time on interfacial charge transport behavior. Unlike concentration-driven structural modification, this work focuses on the evolution of the APS-modified interface governed by reaction time. The DSSC with 30 min APS treatment exhibited the highest power conversion efficiency of 5.34%, representing a 19% enhancement compared to the untreated device (4.49%), mainly due to increased short-circuit current density and open-circuit voltage. However, prolonged coating times (2 h and 24 h) resulted in a significant decrease in photocurrent density, leading to reduced device performance despite partial improvement in recombination resistance. These results are attributed to the time-dependent evolution of the APS interfacial layer. At moderate coating time, APS provides effective surface functionalization, enhancing dye adsorption and suppressing interfacial recombination. In contrast, prolonged coating is expected to induce increased surface coverage and silane condensation, which can hinder electron injection and increase charge transport resistance. Therefore, the photovoltaic performance is governed by a trade-off between recombination suppression and charge injection efficiency, controlled by the silanization time. This study highlights the critical role of interfacial reaction kinetics in determining charge transport behavior and provides an effective strategy for optimizing DSSC performance through time-dependent interface engineering.

In this Paper, we have developed1 a low temperature process to make two type of Paste by using TIO2 nanoprticles(P25). The interconnections between substrate and TiO2 films or link between particles of free-binder Paste (FP1, FPZ, FP3) is very poor. Therefore, the Titanium(IV) isopropoxide was added to the TP paste to improve the interconnection. Electron transport time (Tt) and recombination time (Tr) are analyzed by IMPS (intensity-modulated photocurrent spectroscopy) and INIVS (Intensity-modulated photovltage spectroscopy). In the results, Tt of TP paste based DSSCs (about 4.3×10-3) is faster than other samples. Tt is Ionger from 2.7×10-2 s of FP2 to 3.0×10-2 s of TP. A solar conversion efficiency (DSSCs) of TP 15 3.54% for an incident solar energy of 100 mw cm-2(meanwhile, 2. 70% for DSSCs With FP2). The c아1versioIl efficiency is increased by 1.3 times.