Band-structure design of fluoride complex materials for deep-ultraviolet light-emitting diodes

Abstract

The design principle for fluoride-containing optical devices for applications in the deep ultraviolet range is discussed. Variations in band gap energy, band structure and lattice constant of LiBaxCa ySr(1-X-y)F3 and Li(1-x)K xBa(1-yMgyF3 have been studied. The band structure and transition type of these fluorides are predicted by ab initia band calculations based on the local density approximation. The lattice-matched double-hetero structure of direct-band-gap compounds LiBaxCa ySr(1-x-y)F3 on LiSrF3 and Li( 1-X)KxBa(1-y)MgyF3 on either LiBaFj or KMgFj is sufficiently feasible to fabricate. © 2005 The Japan Society of Applied Physics.