Research on the synthesis of TiO2 thin films with doping mixture of Fluorine and Indium has been carried out. The aim of this research is to produce a thin film which is suitable for use as a component of solar cells, namely the absorbent layer. Synthesis of thin films using the spin-coating method with the help of a modified centrifuge. This research was conducted at the Laboratory of Basic Chemistry and Organic Chemistry, Faculty of Mathematics and Natural Sciences, Mataram University. This type of research is pure experimental research with data analyzed descriptively. The thin layer synthesis process consists of several stages, namely 1). Substrate preparation, 2). Preparation of sol-gel solution, 3). Thin layer deposition, and 4). Heating the thin layer sample. The thin layer sample was given three different treatments consisting of 1). The concentration of the solution, 2). Number of layers, and 3). Variation in sample heating temperature. Based on the research that has been done, it was found that the greater the doping concentration used, the darker the surface of the resulting thin layer sample.