A yellow-emitting phosphor comprised of boron, carbon, nitrogen, and oxygen (BCNO) atoms without any rare-earth ions as luminescence centers was successfully synthesized using a facile process at low temperature and atmospheric pressure. The synthesized BCNO powders showed a broad emission spectrum centered at 540 nm under excitation at 460 nm due to the radiation transitions of local (2)Pi(g) -> (1)Sigma(+)(g) luminescence provided in the BO2- species. Further analysis revealed that the BCNO yellow phosphor exhibited a high external quantum efficiency (60%) having a hexagonal-BN crystalline structure mixed with cubic-B2O3. The synthesized yellow-emitting BCNO phosphor is promising for high-efficiency phosphor conversion-based white light-emitting diodes. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3063063] All rights reserved.