Our research team is dedicated to the design and development of high-performance organic emissive materials, with particular emphasis on thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP). Through precise molecular engineering, we establish clear correlations between molecular structures and excited-state energy levels and dynamics. In TADF systems, donor–acceptor architectures and multiple-resonance (MR) frameworks are employed to effectively reduce the singlet–triplet energy gap (ΔE_ST), thereby promoting reverse intersystem crossing (RISC) and achieving highly efficient utilization of triplet excitons. Simultaneously, molecular rigidity and charge distribution are optimized to realize both high emission efficiency and narrow emission bandwidths. For RTP systems, strategies such as incorporating heavy-atom effects, carbonyl groups, boron atoms, and controlled molecular packing are used to enhance spin–orbit coupling (SOC) and facilitate intersystem crossing (ISC), while suppressing nonradiative decay pathways to prolong triplet lifetimes. This enables stable and long-lived room-temperature phosphorescence. In addition, by integrating host–guest systems and thin-film engineering, we further optimize molecular arrangement and excited-state dynamics, leading to the development of organic emissive materials with high color purity and high efficiency for applications in organic light-emitting diodes (OLEDs) and related optoelectronic devices.