Investigation of the absorption properties of sputtered tin sulfide thin films for photovoltaic applications

Tin sulfide (SnS) is an absorber with promising optoelectronic properties and low environmental constraints of interest for high efficiency solar cells. Sputtered SnS thin films were deposited at target powers 105-155 W and total pressures of 5 to 60 mTorr in argon. X-ray diffraction patterns confirmed a dominant tin monosulfide phase. The absorption coefficient was determined by spectroscopic ellipsometry and unpolarized spectrophotometry measurements. Both methods show that the films have absorption coefficients above the band gap in the range of 10
⁵
-10
⁶
cm
^-1
.