Abstract：Tb complex monomer was copolymerized with N-vinylcarbazole (NVK) and methyl methacrylate (MMA) to give a novel Tb-containing copolymer poly(NVK-Tb(MAA)(acac)2Phen-MMA) (PKMTb), which was characterized with IR and UV-vis spectra to give essentially characteristic absorption of polymethylmethacrylate (PMMA) and polyvinylcabazole (PVK). The copolymer PKMTb's photoluminescent properties were investigated and energy transfer from NVK segment to Tb complex in the copolymer chain was observed. However, this energy transfer was much more efficient in thin solid films than in solution. A single layer device of the structure ITO/PKMTb/Al was fabricated by spin coating from the copolymer chloroform solution, and weak green light emission was observed under positive bias above 14.5 V. The current-voltage (I-V) characteristic of the device shows typical semiconductor diode properties. The working mechanism of the device was also discussed.