Increased p-type conductivity in GaNxSb1-x, experimental and theoretical aspects

Loading...
Thumbnail Image
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal
View/Open full text file from the Research portal
Date
2015-08-28
Major/Subject
Mcode
Degree programme
Language
en
Pages
9
1-9
Series
JOURNAL OF APPLIED PHYSICS, Volume 118, issue 8
Abstract
The large increase in the p-type conductivity observed when nitrogen is added to GaSb has been studied using positron annihilation spectroscopy and ab initio calculations. Doppler broadening measurements have been conducted on samples of GaNxSb1-x layers grown by molecular beam epitaxy, and the results have been compared with calculated first-principle results corresponding to different defect structures. From the calculated data, binding energies for nitrogen-related defects have also been estimated. Based on the results, the increase in residual hole concentration is explained by an increase in the fraction of negative acceptor-type defects in the material. As the band gap decreases with increasing N concentration, the ionization levels of the defects move closer to the valence band. Ga vacancy-type defects are found to act as positron trapping defects in the material, and the ratio of Ga vacancy-type defects to Ga antisites is found to be higher than that of the p-type bulk GaSb substrate. Beside Ga vacancies, the calculated results imply that complexes of a Ga vacancy and nitrogen could be present in the material. (C) 2015 AIP Publishing LLC.
Description
Keywords
POSITRON LIFETIME SPECTROSCOPY, UNDOPED GALLIUM ANTIMONIDE, MOLECULAR-BEAM EPITAXY, AUGMENTED-WAVE METHOD, BAND-GAP REDUCTION, GROWN GANAS, ALLOYS, PHOTOLUMINESCENCE, ANNIHILATION, SEMICONDUCTORS
Other note
Citation
Segercrantz , N , Makkonen , I , Slotte , J , Kujala , J , Veal , T D , Ashwin , M J & Tuomisto , F 2015 , ' Increased p-type conductivity in GaNxSb1-x, experimental and theoretical aspects ' , Journal of Applied Physics , vol. 118 , no. 8 , 085708 , pp. 1-9 . https://doi.org/10.1063/1.4929751