Using tertiarybutylphosphine (TBP) and 1,1-dimethylhydrazine (DMHy) as group V precursors, GaPN films on GaP (001) substrates were successively grown by low-pressure metalorganic vapor phase epitaxy (LP-MOVPE). The maximum N content of GaPN could be achieved to be 7.9% grown at 550 degrees C. In the photoluminescence (PL) measurement at 10 K, the obvious peak could be observed up to 3.8%, and the peak energy was shifted to be 1.88 eV. Compared with the GaPN films grown with PH3 as the P precursor, no additional PL emission related to impurities such as carbon could be observed. From the spectroscopic ellipsometry (SE) measurement, an absorption peak below the indirect gap of GaP and the gradual increase of the absorption intensity between the indirect gap and the fundamental bandgap of GaP were observed with increasing N content. (c) 2006 Elsevier B.V. All rights reserved.