Open AccessDoping effect of boron in Hg0.75Cd0.25Te: first-principles study
Author(s) -
唐冬华,
薛林,
孙立忠,
钟建新
Publication year - 2012
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.61.027102
Subject(s) - dopant , impurity , materials science , vacancy defect , doping , boron , density functional theory , ion , interstitial defect , condensed matter physics , covalent bond , atomic physics , electronic structure , crystallography , molecular physics , computational chemistry , chemistry , physics , optoelectronics , organic chemistry
Using the first-principles method based on the density functional theory, we study the doping effect of B impurity in HgCdTe (MCT).We find that the most stable configuration of the impurity is at the B hexagonal interstitial position, rather than at the in-situ substitution. The electronic structures and the density of states of B hexagonal interstitial doped MCT are systematically investigated. Near neighbour (NN) and next-near-neighbor (NNN) atoms around the B impurity are obviously relaxed. The relaxation induces the breaking of NN Te-Hg covalent bond. Moreover, B hexagonal interstitial behaves as triple n-type dopant. The charged state analysis indicates that Bih(2Hg1Cd) with three positive charges is most stable and forms an effecient donor. However, as long as the Hg vacancy exists, complex impurity between Hg vacancy and B impurity can be easily formed, its binding energy reaches up to 0.96 eV. Such complex behaves as single n-type dopant. Considering radiation damage of B ion implantation, the complex is a main factor restricting the activation of B ion in MCT.