TY - JOUR
T1 - A demonstration of donor passivation through direct formation of V-As_i complexes in As-doped Ge_1−xSn_x
AU - Khanam, Afrina
AU - Vohra, Anurag
AU - Slotte, Jonatan
AU - Makkonen, Ilja
AU - Loo, Roger
AU - Pourtois, Geoffrey
PY - 2020/5/21
Y1 - 2020/5/21
N2 - Positron annihilation spectroscopy in the Doppler and coincidence Doppler mode was applied on Ge_1−xSn_x epitaxial layers, grown by chemical vapor deposition with different total As concentrations (∼10^19–10^21 cm−3), high active As concentrations (∼10^19 cm−3), and similar Sn concentrations (5.9%–6.4%). Positron traps are identified as mono-vacancy complexes. Vacancy-As complexes, V-As_i, formed during the growth were studied to deepen the understanding of the electrical passivation of the Ge_1−xSn_x:As epilayers. Larger mono-vacancy complexes, V-As_i (i≥2), are formed as the As doping increases. The total As concentration shows a significant impact on the saturation of the number of As atoms (i=4) around the vacancies in the sample epilayers. The presence of V-As_i complexes decreases the dopant activation in the Ge_1−xSn_x:As epilayers. Furthermore, the presence of Sn failed to hinder the formation of larger V-As_i complexes and thus failed to reduce the donor-deactivation
AB - Positron annihilation spectroscopy in the Doppler and coincidence Doppler mode was applied on Ge_1−xSn_x epitaxial layers, grown by chemical vapor deposition with different total As concentrations (∼10^19–10^21 cm−3), high active As concentrations (∼10^19 cm−3), and similar Sn concentrations (5.9%–6.4%). Positron traps are identified as mono-vacancy complexes. Vacancy-As complexes, V-As_i, formed during the growth were studied to deepen the understanding of the electrical passivation of the Ge_1−xSn_x:As epilayers. Larger mono-vacancy complexes, V-As_i (i≥2), are formed as the As doping increases. The total As concentration shows a significant impact on the saturation of the number of As atoms (i=4) around the vacancies in the sample epilayers. The presence of V-As_i complexes decreases the dopant activation in the Ge_1−xSn_x:As epilayers. Furthermore, the presence of Sn failed to hinder the formation of larger V-As_i complexes and thus failed to reduce the donor-deactivation
UR - https://aip.scitation.org/doi/10.1063/5.0003999
U2 - 10.1063/5.0003999
DO - 10.1063/5.0003999
M3 - Article
SN - 0021-8979
VL - 127
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 9
M1 - 195703
ER -