Organic molecular beam deposition (OMBD) is used for co-evaporation of copper phthalocyanine (CuPc) and C60 to form mixed films. Although pure single layers are crystalline, mixing leads to amorphous films in most cases, although phase segregation occurs for high concentrations of C60. An underlying CuPc single layer suppresses the segregation and leads to a homogeneous CuPc/C60 mixed film for all layer compositions. These effects are exploited in photovoltaic (PV) devices, where new architectures to improve device performance are investigated. Mixing the CuPc and C60 improves device performance, with the maximum efficiency (ηp = 1.17%) reached for devices containing 75% CuPc in the mixed layer, surrounded by pure layers at the electrode interfaces.