Herein, two new solution-processable HLCT fluorophores (CBzF and CBzFC) based on benzothiadiazole (Bz) derivatives were designed and synthesized (HLCT = hybridized local and charge transfer). Their optical and photophysical properties were experimentally and theoretically studied and verified by the solvatochromic effect and density functional theory calculations. The two molecules demonstrate high solubility, HLCT features, and an intense green fluorescence with solid-state photoluminescence quantum yields of 63-72 %. Both fluorophores are effectively applied as non-doped emitters for solution-processed double-layered OLEDs, which produce intense green emission colors with low turn-on voltages (3.0-3.2 V). Specifically, the CBzFC-based solution-processed device achieves a high maximum luminescence (24400 cd m À 2 ), high maximum efficiencies (EQE max = 5.59 %, CE max = 12.24 cd A À 1 , and PE max = 10.54 lm W À 1 ), and decent efficiency low-off.