Prospects of wide-gap fluoride heterostructures for deep ultraviolet optical devices

Abstract

The design principle of fluoride optical devices for deep ultraviolet applications is discussed. Variations in band gap energy and band structure with respect to the composition are investigated for Li_1−xK_xBa_1−yMg_yF₃ perovskites. The band gap energy, lattice constant, and band structure of perovskite-like fluorides are estimated by the local density approximation based on ab initio calculation. The lattice-matched double-heterostructure with direct band gap compounds Li_1−xK_xBa_1−yMg_yF₃ on either LiBaF₃ or KMgF₃ as substrates are found to be sufficiently feasible to fabricate.