A dual-band photoreceptor using complex Langmuir-Blodgett (LB) films of bacteriorhodopsin (bR) and flavin was constructed. Several conditions such as the number of layers, the electrolyte pH, and the deposition order of two molecules, were examined and analyzed. The optimal fabrication conditions for the proposed dual-band photoreceptor were determined as 10 layers of bR LB films, 6 layers of flavin LB films, the electrolyte pH 7, and the deposition order of ITO/bR/flavin, respectively.