This study aimed to fabricate BT and Bi-doped BT with Bi concentration was varied at 0, 5%, 10%, and 15%. The XRD results revealed that more Bi content caused lattice parameter, volume cell, and crystallite size of BT and Bi-doped BT films to decrease. The BT film possessed the long-grain and largest size among the Bi-doped BT films while Bi doping affected grain size to reduce. The Bi content caused transmittance of the samples to rise and the absorbance to decrease. Bi doping also altered refractive index to reduce. Further, the bandgap values were increased as the more Bi doping.