We report a strategy to induce superconductivity in the BiS2-based compound LaOBiS2. Instead of substituting F for O, we increase the charge-carrier density (electron dope) via substitution of tetravalent Th+4, Hf+4, Zr+4, and Ti+4 for trivalent La+3. It is found that both the LaOBiS2 and ThOBiS2 parent compounds are bad metals and that superconductivity is induced by electron doping with \emph{Tc} values of up to 2.85 K. The superconducting and normal states were characterized by electrical resistivity, magnetic susceptibility, and heat capacity measurements. We also demonstrate that reducing the charge-carrier density (hole doping) via substitution of divalent Sr+2 for La+3 does not induce superconductivity.
@article{arxiv.1303.6216,
title = {Superconductivity induced by electron doping in the system La1-xMxOBiS2 (M = Ti, Zr, Hf, Th)},
author = {D. Yazici and K. Huang and B. D. White and I. Jeon and V. W. Burnett and A. J. Friedman and I. K. Lum and M. Nallaiyan and S. Spagna and M. B. Maple},
journal= {arXiv preprint arXiv:1303.6216},
year = {2013}
}