NOVELTY - Polycrystalline silicon/copper-indium-gallium-selenium overlapped battery is claimed.    USE - Used as a polycrystalline silicon/copper-indium-gallium-selenium overlapped battery.    ADVANTAGE - The polycrystalline silicon/copper-indium-gallium-selenium overlapped battery ensures combined features of a polycrystalline silicon solar battery with a copper-indium-gallium-selenium thin-film solar battery; has improved photoelectric conversion efficiency, high stability and long service life; overcomes problems of an intricate process and high energy consumption during production of the polycrystalline silicon solar battery; solves low good product rate during the production of the copper-indium-gallium-selenium thin-film solar battery; and is cost-effective.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparation of the polycrystalline silicon/copper-indium-gallium-selenium overlapped battery, comprising (i) placing a p-type polycrystalline film (resistance rate of 0.5-3 Omega x cm ) into a mixed acid containing hydrogen fluoride/nitric acid/deionized water, processing flocking for 2-2.5 minutes at 5-8 degrees C to obtain surface texture of polycrystalline silicon, processing phosphorization at 750-850 degrees C in presence of phosphoryl chloride/oxygen, and then washing with hydrogen fluoride/deionized water for removing phosphorus-silicon glass to obtain the lower polycrystalline silicon battery with a p-n junction (square resistance 40-80 Omega /square, (ii) depositing a n+-zinc oxide film on the p-n junction of the lower polycrystalline silicon battery through plasma reinforced chemical vapor deposition method, where a zinc source is diethyl zinc or dimethyl zinc, an oxygen source is a mixed gas of hydrogen and carbon dioxide, and the method comprises vacuumizing a reaction chamber to 1x 10-3 Pa and then heating the lower battery to a deposition temperature of 200-400 degrees C, releasing a carrier gas and a reaction source, filling argon to regulate vacuum degree of a reaction chamber, maintaining a working pressure at 10-100 Pa, adjusting a ratio of the zinc source to the oxygen source at 1:(0.6-0.9), initiating plasma simultaneously, adjusting voltage (Vd) of two electrodes to 200-300 V, depositing for 5-20 minutes and maintaining heat for 5-20 minutes, (iii) growing a copper-gallium-selenium film through polybasic co-evaporation by firstly evaporating metals comprising 99.9999% each of copper, gallium and selenium for 5-20 minutes, controlling the temperature of a substrate at 350-450 degrees C to obtain copper gallium selenide, and secondly evaporating indium, gallium, copper and selenium for 10-30 minutes, controlling the temperature of the substrate at 450-600 degrees C to obtain a p-copper-indium-gallium selenide film, (iv) preparing an i-zinc oxide film by depositing i-zinc oxide through the plasma reinforced chemical vapor deposition, filling argon to regulate the vacuum degree of the reaction chamber, maintaining the working pressure at 10-100 Pa, mainly regulating proportion of the zinc source and the oxygen source to 1:(1.0-1.4), adjusting the voltage (Vd) of the two electrodes to 200-300 V, and depositing for 5-20 minutes, (v) preparing a zinc oxide-aluminum film through magnetron sputtering and using a zinc oxide-aluminum target, filling argon to regulate the working pressure at 4-10 Pa; adjusting the voltage (Vd) of the two electrodes to 200-300 V, depositing for 10-20 minutes, and sputtering for 10-30 minutes, (vi) preparing an upper electrode of the overlapped battery using a nickel-aluminum alloy, evaporating a nickel layer before evaporating an aluminum layer in order to prevent diffusion of aluminum into internal parts of the battery by adjusting the vacuum degree to 1x 10-4 Pa, firstly evaporating nickel and then slowly raising the voltage, opening a baffle, evaporating for 10-20 seconds and then raising the voltage and evaporating for 2-5 minutes, and (vii) preparing a back electrode using the nickel-aluminum alloy by adjusting the vacuum degree to 1x 10-4 Pa, firstly evaporating nickel and then slowly raising the voltage, opening the baffle, evaporating for 10-20 seconds and then raising the voltage and evaporating for 2-5 minutes to complete the preparation of the overlapped battery.