The doping control of GaPN grown by organometallic vapor-phase epitaxy was investigated. The carrier concentration of p-GaPN could be regulated by C self-doping generated from organometallic sources. The carrier concentration of C-doped p-GaPN was controlled by [TBP]/[TEGa] ratio and decreased with increasing N-content due to the formation of acceptor-H complexes. The carrier concentration of S-doped n-GaPN could be controlled by [H2S]/[TBP]. The doping efficiency of the GaPN was decreased to 1/10 as compared with GaP. The ideality factor and series resistance in GaPN pn-junction light-emitting diode on Si were estimated as 7.3 and 17.5 Omega, respectively. We consider that the large ideality factor result from the valence band offset at p-Si/p-GaPN interface. In the light output-current characteristic of the LED, the light output increased nonlinearly in the current range below 10 mA. This indicates that GaPN layers are affected by non-radiative recombination centers. (c) 2008 Elsevier B.V. All rights reserved.