Study On Material And Photovoltaic Properties Of Magnetron Sputtered Sb₂Se₃ Thin Films

As a very important clean and renewable energy,solar energy has attracted more and more researchers'attention in recent years,especially thin film solar cells,which save raw materials,have simple preparation process,short production cycle and low cost.Antimony selenide?Sb₂Se₃?is a new type of semiconductor material.It has the characteristics of suitable optical bandgap,low material cost,high absorption coefficient,stable chemical properties and low crystalline temperature.It is a promising photovoltaic material for solar cell photoabsorber film,and is very suitable for making new low-cost and low-toxicity thin film solar cells.In this paper,antimony selenide thin films were prepared by radio frequency magnetron sputtering by varying sputtering power and substrate temperature.The effects of preparation conditions on antimony selenide thin films and devices were analyzed.Zinc oxide film prepared by magnetron sputtering instead of cadmium sulfide film as buffer layer,the effects of different annealing conditions on zinc oxide thin film and corresponding antimony selenide thin film solar cell devices were analyzed.The main research contents and conclusions are as follows:1)Antimony selenide thin films were prepared by different sputtering power.It was found that the higher the sputtering power was,the faster the deposition rate of the films was,while the E_g calculated and fitted from the transmission curve has little change.2)Antimony selenide thin films were prepared at different substrate temperatures.The higher the substrate temperature was,the lower the deposition rate of antimony selenide film was,the E_g was closer to the normal value,and the lower the ratio of selenium to antimony was.When the substrate temperature was low,XRD has no diffraction peak.When the substrate temperature reaches 300 degrees,a few diffraction peaks appear,and when the substrate temperature is higher than 300degrees,a strong diffraction peak appears.SEM shows that the film has only a few grains when the substrate temperature is low.At higher substrate temperatures,many grains appear on the surface of the films.3)Antimony selenide thin film solar cells are fabricated at different substrate temperatures.It is found that the efficiency is very low when the substrate temperature is less than 250 degrees.When the temperature reaches 250 degrees,there was a low efficiency and the J_sc?short circuit current density?is low too.When the substrate temperature increases gradually,J_sc increases gradually and V_oc?open circuit voltage?changes slightly.When the substrate temperature reaches 350 degrees or higher,J_sc decreases slowly and V_oc decreases sharply.4)Zinc oxide films were prepared by magnetron sputtering,and the effects of different annealing conditions on zinc oxide films were analyzed.It is found that different annealing conditions have little effect on the band gap and the band gap is close to the normal value.For all samples of zinc oxide,there were only two very weak diffraction peaks relevent to zinc oxide.SEM results show that the surface of zinc oxide film is composed of many spherical particles of different sizes,and annealing makes the size of spherical particles of the film surface more uniform.The effect of Annealing on the performance of corresponding devices was analyzed.It was found that the annealing treatment of zinc oxide can improve the open-circuit voltage and filling factor,but reduce the short-circuit current density and with little change in efficiency.