Thin films of CuIn1-xBxSe2 (CIBS) as absorption layer in single-junction solar cells can potentially grant a higher band gap in comparison with other studied chalcopyrite materials like CuIn1-xGaxSe2 (CIGS) and CuIn1-xAlxSe2 (CIAS). The higher band gap near optimum value ~ 1.4 eV can help to achieve higher efficiency (today 19.5% for CuIn0.74Ga0.26Se2). In this paper are described first results of experiments with effort to produce CIBS films by selenization of CuInB precursor alloy in Se vapors. Resulting material was analyzed by Raman spectroscopy, X-ray diffraction, and Auger electron spectroscopy. Measurements show that formation of CIBS layer is complicated by forming of pure CuInSe2 layer with unwanted Cu2-xSe phases and by accumulation boron near to the substrate.