A series of yellow-emitting carbonitride phosphors with compositions of (Y1-xCex)(2)(CN2)(3) (x = 0-0.1) was synthesized by using exothermic solid-state metathesis reactions. The wavelength of the broad band yellow emission was tunable, varying from 570 to 577 nm. The photoluminescence (PL) intensity enhanced with increasing Ce3+ dopant content and was optimized at 3 mol % under excitation at 415 nm. We analyzed the 5d energy levels of Ce3+ in a capped trigonal prismatic complex and estimated the vibronic coupling parameters and Stokes shifts. To understand the thermal quenching behavior, the temperature-dependent PL for (Y1.97Ce0.03)(2)(CN2)(3) was investigated. To demonstrate its potential application, we fabricated a warm white light-emitting diode (LED) using (Y1.97Ce0.03)(2)(CN2)(3), pumped with a 420 nm GaInN LED chip, and the electroluminescence data were also presented. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3476307] All rights reserved.