Quaternary semiconductors with positive crystal field splitting: Potential high-efficiency spin-polarized electron sources.
APPL PHYS LETT
, Article 052102. 10.1063/1.3193662.
Traditional high efficiency spin-polarized electron sources (SPES) consist mainly of binary or pseudobinary zinc-blende GaAs based materials, whereas their ternary analogs II-IV-V-2 (II=Zn, Cd, IV=Si, Ge, Sn, and V=As) as well as II-VI ternary analogs I-III-VI2 (I=Cu, Ag, III=Al, Ga, In, and VI=Se) have not drawn wide attention because their crystal field splitting Delta(CF) near the valence band maximum is either negative or close to zero in their ground state chalcopyrite structure. Using first-principles calculations, we show that some derivative quaternary I-III-II2-VI4 and II-IV-III2-V-4 compounds can have coherent ground state stannite or kesterite structures with large and positive Delta(CF) due to their increased chemical and structural flexibility. We propose that ZnSiAl2As4 and CdGeAl2As4 in the stannite structure, and ZnSnGa2As4 and CuAlCd2Se4 in the kesterite structure could be good candidate SPES materials with high polarization and quantum efficiency.
|Title:||Quaternary semiconductors with positive crystal field splitting: Potential high-efficiency spin-polarized electron sources|
|Keywords:||ab initio calculations, aluminium compounds, cadmium compounds, copper compounds, crystal field interactions, electron spin polarisation, gallium arsenide, germanium compounds, ground states, II-VI semiconductors, silicon compounds, space groups, ternary semiconductors, tin compounds, valence bands, zinc compounds, PHOTOEMISSION, ALLOYS, STRAIN|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry|
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