Polycrystalline ZnSnN2 thin films were successfully prepared by DC magnetron sputtering at room temperature. Both the as-deposited and annealed films showed n-type conduction, with electron concentration varying between 1.6 x 10(18) and 2.3 x 10(17) cm(-3) and the maximummobility of 3.98 cm(2) V-1 s(-1). The basic optical parameters such as the refraction index, extinction coefficient, and absorption coefficient were precisely determined through the spectroscopic ellipsometry measurement and analysis. The optical bandgap of the ZnSnN2 films was calculated to around 1.9 eV, with the absorption coefficient greater than 104 cm(-1) at wavelengths less than 845 nm. The easy-fabricated ZnSnN2 possesses a sound absorption coefficient ranging from the ultraviolet through visible light and into the near-infrared, comparable to some typical photovoltaic materials such as GaAs, CdTe, and InP. (C) 2015 Optical Society of Americ
