## 1 Introduction  
Enhancement of carrier mobility through molecular ordering has been an important issue in operating and optimizing flexible electronic devices that incorporate organic semiconductors [1; 2; 3; 4; 5; 6; 7; 8]. Through various solution processing, particularly, researchers have tuned the crystallinity of the conjugated polymers based on retention of the solution phase in the solidified film phase [9; 10; 11; 12; 13; 14; 15]. Among various pre-deposition treatments including additive engineering, simple solution processing such as sonication-induced molecular ordering has attracted much attention due to dramatic mobility enhancement as well as its facile fabrication method [16; 17; 18; 19; 20]. It is very well-known that ultrasound irradiation induces increased P3 HT chain interactions in solution state through molecular aggregation, where more enhanced \(\pi\)-\(\pi\) stacking is achieved, enabling tuning of molecular crystallinity [9; 16]. [PERSON] et al. demonstrated ultrasound-induced disorder-order transition in P3 HT solutions consistent with enhanced electronic transport in sonicated P3 HT films [9; 21; 22]. Increase in the carrier mobility is explained by improved conjugation of the P3 HT polymer chains, resulting from the anisotropic ordering of the molecules in ultrasound-irradiated solutions. The study also demonstrated tunable crystallinity through ultrasonic irradiation, allowing to control the extent of \(\pi\)-\(\pi\) stacking. Microscopic studies of the P3 HT film morphology have revealed that molecular ordering can be tuned through competition between nucleation and growth mechanisms depending on the degree of supersaturation [21]. Extensive research themes have, however, focused on solidified films in articulating the structure-property relations in conjugated polymers, addressing the origin of the impact of solution treatment on the morphological change in the film state. Several studies have been reported to understand electrical channel formation during solvent evaporation. [PERSON] et al. investigated the in-situ phase transition as a result of a change in the P3 HT chain conformation during solvent evaporation using polarized Raman spectroscopy [16]. Angular-dependent Raman scattering peaks from P3 HT thiophene rings point out that the crystalline phase appears in the formation of a P3 HT conducting channel. The presence of an intermediate phase between isotropic and liquid crystalline phases was inferred from the fact that the vibrational frequency and the full width at half maximum (FWHM) of the C=C stretching mode during solvent evaporation decreased as solidification proceeds. Our previous work addresses the formation of the electrical conducting channel in poly(3-hexylthiophene) (P3 HT) using in situ sheet conductance measurements, revealing the evolution of P3 HT microstructure involving potential phase transitions between isotropic, liquid crystalline, and polycrystalline phases [10]. Fundamental and systematic studies of the in-situ electrical channel formation in which the conformation of the polymer chains are tuned through ultrasonic irradiation, however, have not been reported. As far as we know, comparison of the temporal evolution of the electrical current depending on the extent of nano-crystallites aggregation in forming a conducting channel has not been addressed. Given that electrical current is very sensitive to subtle structural change in solution, comparison between pristine and treated polymer solutions is complementary to in-situ microstructural analysis through conventional microscopic and spectroscopic methods. Here, unlike structure-property correlation based on the ex-situ analytical methods, we focus more on the kinetic-oriented approach in which the final film morphology and crystallinity are tuned through ultrasonic irradiation, resulting in the evolution of the structural arrangement of molecules in the solvent during the solidification process.