## 3 Polystyrene in TIPS Pentacene Crystallization
### High Molecular Weight PS (Greater than 250k)
A binary solvent system composed of anisole and decane was employed which allowed an azeotropic composition with a constant boiling point at 152 \({}^{\circ}\)C as well as a constant solvent composition from evaporation to drying. The increased content of the decane content weakened the interaction between TIPS pentacene  
Figure 11: Cross-sectional EFTEM elemental mapping of silicon elucidates the through-thickness distribution profiles of silicon-containing TIPS pentacene within composite films featuring various PS binders: (**a**) linear, (**b**) four-armed star, and (**c**)entipede configurations. The juncture of each composite film with the underlying SiO\({}_{2}\)/Si substrate is herein denominated as the basal interface, while the uppermost stratum, referred to as the air interface, is overlaid with an Au/Pt coating. Images (**a**,**c**) unmistakably reveal vertical (=) and gradient (\(\Delta\)) phase separation, respectively, whereas the mapping of a TIPS pentacene-enriched region within the laterally aligned (II) star PS composite (**b**) discloses a pronounced concentration of TIPS pentacene near the apical surface. Panel (**d**) illustrates prototypical bead conformations of the three PS architectures, wherein central beads are depicted in black, and the side-chain beads are rendered in distinct hues within the star and centipede configurations. Reproduced from reference [119] and no changes were made, with permission from Wiley ([[https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)]([https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/))) (accessed on 1 September 2024). and the solvent, leading to enhanced nucleation as a result of the formation of H-aggregates. The addition of the PS additive with a higher weight ratio was observed to exert a positive effect on enhancing the TIPS pentacene organic semiconductor film morphology, including improving crystal alignment, enlarging surface coverage, and promoting long range order of the crystals. A maximum mobility of 0.45 cm\({}^{2}\)/Vs was obtained from the thin film transistor based on the mixture of TIPS pentacene and atactic PS at a weight ratio of 95:5. Table 3 summarizes an overview of the studies of TIPS pentacene blended with high molecular weight PS discussed in this section. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Author** & **PS M\({}_{\mathbf{w}}\)** & **Result** & **Mobility** \\ \hline [PERSON] et al. [38] & 280k & \begin{tabular}{c} PS was mixed with TIPS pentacene to tune \\ threshold voltage and charge transport \\ \end{tabular} & 0.85 cm\({}^{2}\)/Vs \\ \hline [PERSON] & 280k & \begin{tabular}{c} PS with mixed with TIPS pentacene to \\ enhance crystal coverage and alignment \\ \end{tabular} & 0.63 cm\({}^{2}\)/Vs \\ \hline [PERSON] et al. [116] & 280k & \begin{tabular}{c} PS vertically phase segregated with TIPS \\ pentacene, yielding crystal alignment along \\ the meniscus coating direction \\ \end{tabular} & 0.51 cm\({}^{2}\)/Vs \\ \hline [PERSON] et al. [117] & 280k & \begin{tabular}{c} PS served as additional gate dielectric \\ to induce electron transport of \\ TIPS pentacene \\ \end{tabular} & \begin{tabular}{c} 4 cm\({}^{2}\)/Vs (hole) \\ and 0.088 cm\({}^{2}\)/Vs \\ (electron) \\ \end{tabular} \\ \hline [PERSON] et al. [118]. & 350k & \
\begin{tabular}{c} PS significantly enhanced the crystal \\ morphology and mobility of TIPS pentacene \\ by increasing crystalline domain size and \\ reducing surface roughness \\ \end{tabular} & 1.82 cm\({}^{2}\)/Vs \\ \hline [PERSON] et al. [119] & 486k,
\begin{tabular}{c} Differing molecular architectures of linear, \\ 4-arm star, and centipede PS significantly \\ influence the phase separation behavior and \\ the charge mobility in TIPS pentacene \\ blend films \\ \end{tabular} & 0.45 cm\({}^{2}\)/Vs \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Overview of the studies on TIPS pentacene blended with PS of high Mw, highlighting the author, Mw, result and mobility from each study.