Force-Light-Electric Three-Dimensional Dynamic Mechanism of Room-Temperature Phosphorescence Materials under Hydrostatic Pressure.

Adaptive deformation display technology imposes new demands on core materials and devices, as traditional mechanical and structural flexibility struggles to meet the requirements of high resolution and high reliability. Intrinsically flexible molecular materials that combine mechanical deformation properties with optoelectronic functionalities offer a unique technological pathway for adaptive deformation displays. However, current research predominantly focuses on the single-dimensional properties of room-temperature phosphorescence (RTP) materials, which limits a comprehensive understanding of their stimuli-responsive properties. In this study, we select nine molecules based on phenothiazine (PTZO) and trifluoromethyl (CF) substituted derivatives, systematically investigating the luminescence and charge transport properties under hydrostatic pressure (0-6 GPa). This work is the first to achieve a unified characterization of individual molecular performance in a three-dimensional force-light-electric model, revealing the complex coupling mechanisms among molecular structures, molecular packing modes, excited-state regulations, and stimuli-responsive properties. The nine molecules exhibit distinct pressure-induced response characteristics. In particular, PTZO-2CF derivatives demonstrate unique pressure-responsive behavior with their emission wavelength and spin-orbit coupling (SOC) strength showing monotonic changes under pressure, primarily due to the strong electron-absorbing effect and steric hindrance of the two CF groups. The radiative decay rates of all molecules remain stable under varying pressures, indicating that pressure has a weak influence on the intrinsic electronic structure and transition dipole moments. In contrast, the nonradiative decay rates decrease with increased pressures, due to the reduction of free volume and suppression of molecular vibrations, which enhances luminescence efficiency. Most of the investigated molecules exhibit hole-dominated charge transport, with both hole and electron mobilities enhanced under pressure. Interestingly, PTZO-H-3F shows electron-dominated behavior, attributed to its significantly lower electron reorganization energies, which facilitate more efficient electron transport. Notably, PTZO-H-2F exhibits pressure-induced bipolar transport at 3 GPa, highlighting its potential as a tunable platform for pressure-responsive organic emitters. Thus, the "force-light-electric" three-dimensional dynamic processes under hydrostatic pressures are revealed, providing new insights for designing high-performance intrinsically flexible molecular materials and advancing innovative adaptive deformation display technology.