SrSi2O2N2: Eu2+ green phosphors are prepared using a convenient solid-state reaction with Sr2SiO4: Eu2+ as the precursor. The activation energy of crystallization, electron-phonon coupling, and thermal quenching behavior are investigated using differential thermal analysis (DTA) spectra and photoluminescence measurements. SrSi2O2N2: Eu2+ green phosphors exhibit excellent thermal stability and color stability due to their weak electron-phonon coupling strength (Huang-Rhys factor 4.2). The thermal quenching temperature (T-50) of SrSi2O2N2: Eu2+ is above 200 degrees C. Results show that SrSi2O2N2: Eu2+ green phosphors have a broad excitation band and good thermal stability, making them suitable for use in solid-state lighting and GaAsAl solar cells. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3600349] All rights reserved.