Programmable digital printing of organic single crystals for integrated electronics

Precise control over orientation and crystallinity in additive manufacturing (AM) of organic semiconductor arrays is critical for achieving high-performance organic integrated electronics. However, achieving such control in conventional AM remains particularly challenging without engineered spatial constraints due to the complex crystallization kinetics of small-molecule organic semiconductors under nonequilibrium ink deposition conditions. Here, we report a simple yet effective mask-free, pattern-free printing of high-resolution organic single-crystal arrays with controlled location, orientation, and aspect ratio. Central to this method is the establishment of a dynamic liquid-crystal area (DLCA) beneath the nozzle, which governs the kinetically coupled interplay of solute transport, solvent evaporation, and nucleation. By tuning DLCA geometry via applied voltage and speed, the random nucleation and anisotropic crystal growth is suppressed. This mechanism, supported by classical theory and transition region theory, is universally applicable to most solution-processable high-performance small-molecule organic semiconductors. The organic single crystal array exhibits highly uniform mobility, with around 12 to 15% variation, representing the most uniform organic single-crystal arrays achieved by electrohydrodynamic printing so far. In addition, the printed organic single-crystal patterns can be successfully integrated into a functional 96 organic field-effect transistor photodetector array, demonstrating their potential for information recognition and organic integrated electronics.