Structural, optical and electro-optical properties of thermally evaporated SnS layers

Tin sulphide (SnS) films have been grown by thermal evaporation onto glass substrates under different substrate temperatures, Ts varying in the range, 280-360oC, with other growth parameters kept constant. The X-ray diffraction studies showed a strong (040) orientation and the layers had leaf-like surface topology as observed from scanning electron microscopy. The energy band gap, measured from optical studies, varied in the range 1.3-1.34 eV while the absorption coefficient was >104cm-1.The refractive index, extension coefficient and other optical parameters were also calculated. The electrical resistivity of the films decreased with increase of substrate temperatures. Heterojunction devices were made using chemical bath deposited CdS as window layer and the minority carrier diffusion lengths were measured using the spectral response studies.