摘要：The donor-n-conjugated-acceptor （D-n-A） structure is an important design for the luminescent materials be- cause of its diversity in the selections of donor, n-bridge and acceptor groups. Herein, we demonstrate two examples of D-^-A structures capable to finely modulate the excited state properties and arrangement of energy levels, TPA-AN-BP and CZP-AN-BP, which possess the same acceptor and n-bridge but different donor. The investigation of their photophysical properties and DFT calculation revealed that the D-n-A structure with proper donor, n-bridge and acceptor can result in separation of frontier molecular orbitals on the corresponding donor and acceptor with an obvious overlap on the n-bridge, resulting in a hybridized local and charge-transfer （HLCT） excited state with high photoluminescent （PL） efficiencies. Meanwhile, their singlet and triplet states are arranged on corresponding moie- ties with large energy gap between T2 and T1, and a small energy gap between S1 and T2, which favor the reverse intersystem crossing （RISC） from high-lying triplet levels to singlet levels. As a result, the sky-blue emission non-doped OLED based on the TPA-AN-BP reached maximum external quantum efficiency （EQE） of 4.39% and a high exciton utilization efficiency （EUE） of 77%. This study demonstrates a new strategy to construct highly effi- cient OLED materials.