Research On Metal Chalcogenide Materials And Its Application In Solar Cells

Organic solar cells and antimony sulphide solar cells have attracted much attention in recent years.Because of its simple manufacture,low cost,rich content of needed elements in nature and so on,organic solar cells have attracted much attention and researchs in today's era,and have broad prospects.It is also a bright spot in the application of flexible solar cells.In recent years,more and more people began to study antimony sulfide solar cells,and many excellent works were published one by one.Due to the excellent stability,adjustable band gap and easy crystallization,antimony sulfide may occupy a place in the commercial application of solar cells.In this paper,several metal sulfide compounds and their applications in solar cells are studied,which provides a new possibility and direction for the future solar cells.The CuxAl1-xSy thin films with adjustable band gap were successfully prepared by changing the composition ratio of precursor solution in low temperature chemical bath deposition.The effects of annealing temperature and composition ratio on the properties of CuxAl1-xSy films were studied in detail.It is found that CuxAl1-xSy thin films have the characteristics of adjustable band gap width(2.63-4.01 eV),high hole mobility and visible light transmittance.Because they also have the advantages of good stability,non-toxicity and high content of earth elements,organic solar cells are prepared by using CuxAl1-xSy thin films as hole transport layer.Through optimization,it is found that 40 nm CuxAl1-xSy film has the best performance in P3HT:PCBM polymer solar cell as hole transporting layer.The optimal performance of the battery can be obtained when the mole ratio of Cu-Al element in precursor solution is 5:5.The photoelectric conversion efficiency is 2.67%and the band gap width of CuAlS2 film is 3.66 eV.Nowadays,commercial transparent conductive materials are usually N-type,P-type transparent conductive materials are very difficult to prepare.In this paper,CuAlS2 thin films were used as P-type transparent electrode materials to fabricate P3HT:PCBM organic solar cells,and the photoelectric conversion efficiency of 0.32%was obtained.It is suggested that the amount of ammonia and thiourea can be greatly reduced by using low concentration cadmium chloride,ammonium chloride,ammonia and thiourea as raw materials.The preparation method of cadmium sulfide in antimony sulfide solar cells was improved.This not only saves raw materials,but also greatly reduces pollution and improves utilization ratio of materials.Ag is used as metal electrode to replace expensive Au electrode,which greatly reduces cost and obtains considerable efficiency.The preparation process of battery with FTO/CdS/Sb2S3/Spiro-OMeTAD/Ag structure was studied comprehensively and systematically.The preparation of cadmium sulfide layer and process parameters of CdCl2 modification were optimized in detail,including solution concentration,environmental humidity,film thickness and annealing temperature in order to obtain the optimal battery performance.It is found that when cadmium sulfide thin films are treated with 4 mg/mL CdCl2 methanol solution,the open circuit voltage of the battery will increase to 0.725 V(one of the highest reported values in the world).It is found that the best battery performance is achieved when CdCl2 modified layer is rotated at 30%ambient humidity.It is confirmed that the optimum thickness of cadmium sulfide is 80 nm,and cadmium sulfide film modified with saturated CdCl2 methanol solution and annealed at 400? for 10 min is the optimum film.Antimony sulfide thin films were synthesized by simple and environmentally friendly hydrothermal method.The effect of antimony sulfide thickness on the performance of the battery and the effect of annealing temperature on the morphology of antimony sulfide thin films and the performance of related antimony sulfide solar cells were systematically studied.It is confirmed that the optimum thickness of antimony sulfide is 290 nm,.The optimum annealing condition is annealing at 350 ?for 10 min.Combined with the above optimal regulation,antimony sulfide solar cells with open circuit voltage of 0.675 V,short circuit current density of 14.23 mA/cm2,filling factor of 46.57%and photoelectric conversion efficiency of 4.47%were obtained.Antimony sulfide solar cells are assumed to be ideal single heterojunction solar cells.Based on the ideal model of single heterojunction solar cell,the series resistance,ideal factor,reverse saturation current density and theoretical open-circuit voltage of antimony sulfide solar cell are calculated according to the experimental data of J-V characteristic curve.According to the corresponding theoretical calculation,the series resistance is 56.52 ?·cm2,the ideal factor is 1.11,the reverse saturation current density is 1.87×10-9 mA/cm2.The theoretical open-circuit voltage is 0.654 V,which is close to the measurement value of 0.665 V.