TY - JOUR
T1 - Intrinsic stoichiometry and oxygen-induced p-type conductivity of pyrite FeS2
AU - Sun, Ruoshi
AU - Chan, M. K.Y.
AU - Kang, Shinyoung
AU - Ceder, G.
PY - 2011/7/11
Y1 - 2011/7/11
N2 - The stoichiometry and ubiquitous observation of p-type conductivity of synthetic pyrite FeS2 thin films are investigated via first-principles computations of native (vacancies, interstitials, antisites) and extrinsic (OS, Oi) point defects. Native defects have high formation energies and are predicted to occur in low concentrations within the Fe- and S-rich limits, showing that pyrite should be intrinsically stoichiometric. Under sufficiently oxidizing conditions, OS becomes the most dominant defect type and induces p-type conductivity. At the experimental oxygen impurity concentration, the hole concentration is predicted to be O(1019) cm-3, in agreement with Hall measurements reported in the literature. Therefore, we attribute the unintentional p-type conductivity of pyrite to oxygen impurities and propose that improvements in device performance may be achieved under more reducing conditions.
AB - The stoichiometry and ubiquitous observation of p-type conductivity of synthetic pyrite FeS2 thin films are investigated via first-principles computations of native (vacancies, interstitials, antisites) and extrinsic (OS, Oi) point defects. Native defects have high formation energies and are predicted to occur in low concentrations within the Fe- and S-rich limits, showing that pyrite should be intrinsically stoichiometric. Under sufficiently oxidizing conditions, OS becomes the most dominant defect type and induces p-type conductivity. At the experimental oxygen impurity concentration, the hole concentration is predicted to be O(1019) cm-3, in agreement with Hall measurements reported in the literature. Therefore, we attribute the unintentional p-type conductivity of pyrite to oxygen impurities and propose that improvements in device performance may be achieved under more reducing conditions.
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U2 - 10.1103/PhysRevB.84.035212
DO - 10.1103/PhysRevB.84.035212
M3 - Article
AN - SCOPUS:79961216343
SN - 1098-0121
VL - 84
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 3
M1 - 035212
ER -