Electronic structure of Ga
Cr
N and Si-doping effects studied by photoemission and X-ray absorption spectroscopy
光電子分光及びX線吸収分光により調べたGa
Cr
Nの電子構造とそのSi添加による影響
Song, G.*; 小林 正起*; Hwang, J. I.*; 片岡 隆*; 滝沢 優*; 藤森 淳; 大河内 拓雄; 竹田 幸治
; 岡根 哲夫
; 斎藤 祐児
; 山上 浩志; Chang, F.-H.*; Lee, L.*; Lin, H.-J.*; Huang, D.-J.*; Chen, C. T.*; 木村 重哉*; 船越 政行*; 長谷川 繁彦*; 朝日 一*
Song, G.*; Kobayashi, Masaki*; Hwang, J. I.*; Kataoka, Takashi*; Takizawa, Masaru*; Fujimori, Atsushi; Okochi, Takuo; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Yamagami, Hiroshi; Chang, F.-H.*; Lee, L.*; Lin, H.-J.*; Huang, D.-J.*; Chen, C. T.*; Kimura, Shigeya*; Funakoshi, Masayuki*; Hasegawa, Shigehiko*; Asahi, Hajime*
The electronic structure of the magnetic semiconductor Ga
Cr
N, and the effect of Si doping on it have been investigated by photoemission and soft X-ray absorption spectroscopy. We have confirmed that Cr in GaN is predominantly trivalent when substituting for Ga and that Cr 3
states appear within the band gap of GaN just above the N 2
-derived valence-band maximum. As a result of Si doping, downward shifts of the core levels (except for Cr 2
) and the formation of new states near the Fermi level were observed, which we attribute to the upward chemical-potential shift and the formation of a small amount of Cr
species caused by electron doping. Possibility of Cr-rich cluster growth by Si doping are discussed based on the spectroscopic and magnetization data.