Open AccessFirst principles investigation on conductivity mechanism of p-type K:ZnO
Author(s) -
Yang Yin-Tang,
Wu Jun,
Cai Yu-Rong,
Ding Rui-xue,
Jiuxu Song,
Lichun Shi
Publication year - 2008
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.57.7151
Subject(s) - conductivity , acceptor , doping , materials science , density functional theory , vacancy defect , zinc , valence (chemistry) , band gap , hydrogen , condensed matter physics , computational chemistry , chemistry , optoelectronics , physics , metallurgy , organic chemistry
The electronic structures of potassium doped ZnO have been calculated by first principles plane wave-function psuedopotential approach based on density-functional theory and local density approximation. Properties of some defects were studied in order to explicate the conductivity mechanism of p-K:ZnO, including hydrogen interstitial (Hi), oxygen vacancy (VO), zinc interstitial (Zni) and zinc vacancy (VZn). The calculated results revealed that: (1) K-doping introduced a shallow acceptor,besides increasing the system total energy simultaneously. (2) K-H:ZnO decreased the system energy and increased the system stability. (3) Although the formation of VO was more difficult than that of Zni, both of them were electronegative centers and played a role in compensating for the acceptors. (4) VZn produceda shallow acceptor approximately 0.5 eV above the maximum valence band, which was beneficial for p-type conductivity. Finally, it was proposed that the realization of p-type conductivity in K:ZnO may be due to the formation of a KZn-O-Hi-O-VZn complex.