Open AccessElectronic structures and optical properties of boron and phosphorus doped β-Si3N4
Author(s) -
Cheng Chao-Qun,
Gang Li,
Wendong Zhang,
Pengwei Li,
J. F. Hu,
Sang Sheng-Bo,
Xiao Deng
Publication year - 2015
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.64.067102
Subject(s) - doping , materials science , pseudopotential , boron nitride , band gap , dielectric , condensed matter physics , silicon , electronic structure , boron , molecular physics , atomic physics , optoelectronics , nanotechnology , chemistry , physics , organic chemistry
The electronic structures and optical properties of boron/phosphorus mono- and co-doped β silicon nitride are studied by the first-principles plane-wave ultrasoft pseudopotential method with the generalized gradient approximation. The results are obtained as follows. The B-doped system has a better stability than the P-doped system, while the P-doped structure has a stronger ionicity. The mono-doping and co-doping can narrow the band gap of β silicon nitride while the co-doping introduces the deep impurity levels and strengthens the localized states. The mono-doping causes the imaginary part of dielectric function, the peaks of absorption spectra and energy loss spectra to red-shift, and their amplitudes to decrease, resulting in a significant difference from the intrinsic state. The co-doping induces the peak of imaginary part of the dielectric function to blue-shift, broadens the energy loss peak, greatly enhances the electronic transition in the high energy region, and controlling the ratio of the numbers of atoms (B and P) in co-doping can achieve a low charged defect concentration, implying its potential application in the field of microelectronics.