Optical study of resonant states in GaN _x As_1−x

Abstract

To detect resonant states in the conduction band of GaN_xAs_1−x , it is suggested to study the spectra of intrinsic photoluminescence at room temperature or under high-level excitation, which fills high-energy states in the allowed bands with carriers excited by light. Energy levels within the conduction band of bulk GaN_xAs_1−x (x ≤ 0.015) layers were detected by the suggested method. These levels form a band of about 0.07 eV in half-width, with its density-of-states peak lying at ∼1.4 and ∼1.48 eV above the top of the valence band at temperatures 290 and 80 K, respectively. The position of this peak with respect to the valence band is virtually independent of the nitrogen content for all the studied range, 0.0005 ≤ x ≤ 0.015. It is assumed that these states are related to different clusters of nitrogen atoms.