Experimental evidence for N-induced strong coupling of host conduction band states in GaNxP1-x:: Insight into the dominant mechanism for giant band-gap bowing -: art. no. 201303

Direct evidence for N-induced strong coupling of host conduction band (CB) states in GaNxP1-x is provided by photoluminescence excitation. It is manifested as: (1) a drastic change in the ratio of oscillator strengths between the optical transitions involving the CB minimum (CBM) and the high-lying Gamma CB state; (2) a strong blueshift of the Gamma CB state with increasing x accompanying a redshift of the CBM, (3) pinning of the localized N states and a newly emerging t(2) (L or X-3) CB state. These findings shed new light on the issue of the dominant mechanism responsible for the giant band-gap bowing of dilute nitrides.