Letting Polymer Semiconductors Crystallize Along Their Self-Templates: A Self-Templated Gradient Assembly Strategy for Multi-Scale Structural Ordering and Ultrahigh Charge Carrier Mobility

• • The STGA strategy employs a solvent-selection matrix defined by two orthogonal parameters—relative energy difference (RED) and vapor pressure—to decouple and control solution-state aggregation from assembly kinetics. This replaces empirical trial-and-error solvent selection with predictive design rules, directly addressing the industrial bottleneck of batch-to-batch mobility variance in printed organic electronics. • • Cryo-TEM validation demonstrates that primary aggregate size systematically enlarges as solvent quality decreases, confirming RED as a quantitative predictor of solution aggregation. This provides a measurable process control parameter (RED) that can be monitored inline during ink formulation, reducing costly trial-and-error in roll-to-roll manufacturing. • • The side chain/backbone parameter Ratio (S/B) distinguishes aggregation pathways induced by different poor solvents for low-solubility, low-volatility components, enabling selective promotion of backbone π–π stacking over side-chain disorder. This selectivity is critical for maximizing interchain hopping and minimizing grain boundary resistance in high-mobility polymer semiconductors. • • The resulting single-crystal-like polymer semiconductors achieve ultrahigh charge carrier mobility, as reported in Nat Mater 2026 (doi: 10.1038/s41563-026-02670-y). This performance metric directly challenges the dominance of amorphous silicon and organic small-molecule semiconductors in flexible display backplanes, where mobility thresholds of >1 cm² V⁻¹ s⁻¹ are required for high-refresh-rate driver circuits.