This article describes the synthesis and luminescent properties of two carbazole-functionalized 2-(benzo[d]thiazol-2-yl)phenol ligands (BTZ-Cz-OH and BTZ-DCz-OH) and their difluoroboron complexes (BTZ-Cz-BF and BTZ-DCz-BF) as the emitting materials. All of the emitting materials were characterized by NMR (¹H and ¹³C) spectroscopy, high-resolution mass spectroscopy and elemental analysis, and they possess good thermal and electrochemical stabilities. The ligands exhibit green emission in solution and solid thin films due to the characteristics of excited-state intramolecular proton-transfer (ESIPT). Upon coordination to the difluoroboron complexes, a significant blue-shift and enhanced emission is observed due to the restricted conformation change. These materials are successfully used as the doped emitters in organic light-emitting diodes (OLEDs), and all the doped devices exhibit strong emission with low turn-on voltages (3.9–4.8 V), and the doped devices based on the difluoroboron complexes exhibit better EL performances than that of the ligands. Especially, the doped device of BTZ-Cz-BF with the dopant concentration of 10 wt% shows the best EL performances with a maximum luminescence of 3940 cd/m², a maximum current efficiency of 8.26 cd/A and a maximum external quantum efficiency (EQE) of 3.34%.