Based On The Zno Thin Film Amorphous Silicon Solar Cell Research

Facing the problem of the global energy shortage and environmental pollution, solar photovoltaic power generation is one of the efficient solution way, so the study of low-carbon and efficient solar cells is around the corner. According to the solar cell material properties and considering the cost of materials, environmental protection, energy consumption, the improving of solar cells efficiency and other factors, the new solar cell material is researched in this subject and the structure of AlN:Mg/a-Si:H/ZnO:Al and NiO/a-Si:H/ZnO:Al solar cells are prepared. Contents and conclusions in this paper are as follows:1. The AlN:Mg thin film is deposited by DC reactive magnetron sputtering and the ZnO:Al thin film is deposited by RF magnetron sputtering. The experimental results show that the sputtering rate of AlN:Mg thin film is about8nm/min (within30minutes). The Sputtering conditions are that the content of aluminum-magnesium alloy target is5%, the proportion of sputtering gas Ar and O2is1:1, the sputtering pressure is6.5×10-1Pa, the sputtering power is90W, the sputtering temperature is100℃and the target-substrate distance is75mm. When the sputtering time is30minutes, the film thickness is about200nm;The AlN:Mg thin film made by magnetron sputtering, lower than the target atomic ratio(19:1), so we can see magnesium atomic ratio of aluminum atom is more easily sputtered on the substrate in the sputtering process; The surface morphology of AlN:Mg thin film is compact and has better light transmission; The AlN:Mg/ZnO:Al thin film has not only the good characteristics of PN junction rectifier, but also has high average transmittance (≥85%) in the visible light band.2. The NiO thin film is deposited by DC reactive sputtering and the ZnO:Al thin film is deposited by RF reactive sputtering. The changes of film properties and their performance results of the PN junction before and after annealing process are researched. The annealing conditions are that the temperature increasing rate is10℃/min, the annealing time is two hours and the temperature decreasing rate is not higher than5℃/min. The experimental results show that the transmittance, optical band gap, crystal structure, electrical conductivity and the ingredients etc have changed after annealing. The higher the annealing temperature is, the more obvious the change is. When the nitrogen annealing temperature is400℃, the transmittance of NiO film in the visible region increases from10%to more than80%after annealing; The optical band gap (Eg) of NiO thin film also decreased slightly; The Orientation diffraction peak of NiO thin film crystal structure is more obvious. The thickness of the NiO film is about145nm. The resistance is floating up and down4KΩ/(?) after annealing and its film conductivity is maintained at about5.8x10-4Ω·m; When the temperature is higher, the effect of nitrogen annealing is the more obvious. When the temperature increase, it is more easily lead to the introduction of the film with a nitrogen atmosphere of nitrogen molecules, resulting in film composition change and the changing of semiconductor properties. The experimental study found that the ZnO:Al film characteristics changes are not so obvious like NiO film. The heterojunction junction PN junction rectifier characteristics of NiO/ZnO:Al thin film changes after annealing. That means the rectifying behavior is more obvious with the increasing of annealing temperature and when the temperature is400℃, the Rectifying behavior is the best.3. The a-Si:H film is prepared by PECVD. The AlN:Mg/a-SI:H/ZnO:Al and NiO/a-Si:H/ZnO:Al thin film heterojunction solar cells are prepared, using the theory of HIT cells with amorphous silicon cells. The cell performance and feasibility of the two structures are tested and the effect of NiO/a-Si:H/ZnO:Al thin film heterojunction solar cells is also analysed. The experimental results show that the open circuit voltage of AlN:Mg/a-Si:H/ZnO:Al silicon cells is1.2V, the short-circuit current is0.08mA, the photoelectric conversion efficiency is1.02%; The conversion efficiency of NiO/a-Si/ZnO:Al cell is about1.1%after2hours400℃nitrogen anneal, but open circuit voltage of NiO/a-Si/ZnO:Al cells becomes lower from the original1.3V down to1.1V.