Steinmann, VeraBrandt, Riley E.Chakraborty, RupakJaramillo, RafaelYoung, MatthewOfori-Okai, Benjamin K.Yang, ChuanxiPolizzotti, AlexNelson, Keith A.Gordon, RoyBuonassisi, Tonio2016-07-112016Steinmann, Vera, Riley E. Brandt, Rupak Chakraborty, R. Jaramillo, Matthew Young, Benjamin K. Ofori-Okai, Chuanxi Yang, et al. 2016. “The Impact of Sodium Contamination in Tin Sulfide Thin-Film Solar Cells.” APL Materials 4 (2) (February 1): 026103. Portico. doi:10.1063/1.4941713.2166-532Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:27531387Through empirical observations, sodium (Na) has been identified as a benign contaminant in some thin-film solar cells. Here, we intentionally contaminate thermally evaporated tin sulfide (SnS) thin-films with sodium and measure the SnS absorber properties and solar cell characteristics. The carrier concentration increases from 2× 10^16cm^−3 to 4.3×10^17cm^−3 in Na-doped SnS thin-films, when using a 13 nm NaCl seed layer, which is detrimental for SnS photovoltaic applications but could make Na-doped SnS an attractive candidate in thermoelectrics. The observed trend in carrier concentration is in good agreement with density functional theory calculations, which predict an acceptor-type NaSn defect with low formation energyen-USJournal Article2016-03-0120162016-07-1110.1063/1.4941713