Confirmation of the impurity-band model for GaP1-xNx -: art. no. 073203

Low-temperature absorption studies on freestanding GaP1-xNx films provide direct experimental evidence that the host conduction band minimum (CBM) near X-1C does not plunge downward with increased nitrogen doping contrary to what has been suggested recently, but in fact remains stationary for x up to 0.1%. This, combined with the results of earlier studies of the CBM at Gamma and conduction band edge near L, confirms that the giant band-gap lowering observed in GaP1-xNx results from a CBM that evolves purely from nitrogen impurity bands.