Structural, optical, and electrical properties of strontium-doped tin dioxide films for high photoconductivity

In this work, tin dioxide (SnO 2) films with different concentrations of strontium (Sr) were prepared using sol-gel and immersing methods. The structural, morphological, optical, and electric properties of Sr -doped SnO 2 films were investigated for photoconductivity applications. X-ray diffraction patterns revealed a tetragonal rutile structure for the deposited films with lattice parameters (a = b = 4.726 & Aring;, c = 3.182 & Aring;). Adding 4.71 at.% of Sr (optimal doping ratio) into SnO 2 film leads to a significant decrease in the crystallite size. Consequently, the highest electrical conductivity of Sr -doped SnO 2 films is attained at 4.71 at.%. The transmittance and optical bandgap of Sr -doped SnO 2 films exhibit a significant decrease at a high Sr doping ratio of 10.07 at.%. Additionally, the electrical conductivity of undoped SnO 2 and Sr -doped SnO 2 (4.71 at. %) films increases from 0.22 S/ cm and 2.18 S/cm to 0.43 S/cm and 4.95 S/cm under UV -irradiation, respectively, with good consistency and repeatability. The findings of this work indicate that Sr-doped-SnO 2 films are potential candidate materials for a wide range of applications, especially photoconductivity, photodetectors, and photoconductive materials.