Electronic band structures of filled tetrahedral semiconductor LiMgP and zinc-blende AlP

摘要

The band structures of the filled tetrahedral semiconductor LiMgP and zinc-blende AIP were studied using the full potential linearized augmented plane wave method (FP-LAPW). The conduction band modifications of LiMgP, compared to its 'parent' zinc-blende analog AIP, are discussed. It was found that the conduction band valleys of LiMgP follow the X-T-L ordering of increasing energy for both alpha (Li+ near the anion) and beta(Li+ near the cation) phases, whereas AIP has the X-L-F ordering, and the differences between the direct (Gamma-Gamma) and indirect (Gamma-X) gaps decrease in the alpha and beta-LiMgP, compared to AIR The interstitial insertion of closed-shell Li+ ion is a possible method to change the direct-indirect gap nature, but the 'interstitial insertion rule' cannot be applied in predicting all conduction band modifications of LiMgP, relative to AIR The total energy calculations show the a phase to be more stable than the 0 phase for LiMgP. (c) 2005 Elsevier Ltd. All rights reserved.