| With the increasing shortage of fossil energy and the continuous deterioration of the global environment,all countries in the world are actively developing clean solar energy.Solar cells can directly convert solar energy into electrical energy,which is the most feasible way to use solar energy.Thin film solar cells are a very competitive one due to the advantages of less material and easy preparation.The newly rising antimony selenide?Sb2Se3?thin film solar cells have received much concern because of their own unique advantages,with a rapid increase of efficiency up to 6.5%in the last four years.The National Energy Bureau"energy technology innovation"in 13th Five-Year"plan"has documented Sb2Se3 thin film solar cells to be one of the key new technologies for high-efficiency and low-cost photovoltaic devices.At present,there are many methods to prepare Sb2Se3 films,such as chemical water bath deposition,rapid thermal evaporation,spin coating and so on.As a common method for preparing industrial thin films,the magnetron sputtering method is seldom studied.Although Sb2Se3 thin-film solar cell technology is currently receiving widespread attention,due to the difficulty in the preparation of high-quality Sb2Se3,its current efficiency is still relatively low.Magnetron sputtering method can effectively reduce the crystallization temperature of Sb2Se3 thin film due to the high SbxSey energy sputtered out,so that the typical 300°C crystal growth temperature of thermal evaporation is further reduced,thus,expecting to obtain high quality Sb2Se3 thin film material.Based on a thorough literature review and the above-mentioned issues in the field of Sb2Se3 thin-film solar cells,this research paper has carried out a series of research and discussion on the preparation of Sb2Se3 thin-film solar cells by magnetron sputtering as followings:?1?Based on the experience of post-metal selenization of copper indium gallium selenide?CIGS?thin-film solar cells,we first tried to prepare metal pre-layers by magnetron sputtering of Sb target,and followed by the selenization under Se atmosphere in a rapid annealing furnace to prepare Sb2Se3 film.By adjusting the annealing temperature,Sb2Se3 thin films with pure phase and good surface crystallinity were obtained.The optimum efficiency of Sb2Se3 thin film solar cells is 0.68%,with a short-circuit current density of 10.41 mA/cm2.Inductively coupled plasma spectrometer?ICP?results show that the post-selenization after metal Sb is easy to be Sb-rich,which is not suitable for high-efficiency Sb2Se3thin-film solar cells.?2?The alloy sputtering method has the advantage of ensuring that the composition of the prepared film,being basically the same as that of the target.Based on this,the Sb2Se3 thin film with a Sb2Se3 alloy target was sputtered.The structure evolution of sputtered Sb2Se3 films was investigated by heating the substrate with different temperatures during sputtering.A series of characterization on the sputtered Sb2Se3films,were performed,such as scanning electron microscopy?SEM?,X-ray diffraction?XRD?,Raman spectroscopy,and inductively coupled plasma spectroscopy?ICP?,to study the optical characteristics and electrical properties of Sb2Se3 films grown at different temperatures.The results show that the substrate temperature has a great influence on the grain size,densification,crystal orientation and atomic vibration.The film has better properties when the substrate temperature is 350?.Based on this,a solar cell with a?SLG/FTO/Sb2Se3/ZnO/ITO/Ag?structure was constructed,and a photovoltaic conversion efficiency of0.98%was initially obtained.?3?Preparation of Sb2Se3 thin films by magnetron sputtering Sb2Se3 binary alloy targe without substrates heating,we found that preparation of amorphous Sb2Se3 film rich Se state.Rich Se film can effectively inhibit the formation of deep defects,promote the formation of shallow defects.So we presented Sb2Se3 heterojunction solar cells synthesized by annealing of the sputtered Sb2Se3 thin film through a rapid thermal process.A prototype substrate Mo/Sb2Se3/CdS/ZnO/ITO/Ag solar cell was built and 3.09%device efficiency?Voc=343 mV,Jsc=19.8 mA/cm2,FF=45.6%?was obtained under simulated AM 1.5G irradiation.The morphology and structure were confirmed to be improved by rising the annealing temperature.The solar cell with efficiency as high as 3%has been achieved with the Sb2Se3.Our studies demonstrated that annealing temperature is a crucial factor for the solar cell performance.Proper temperature will significantly improve the efficiency of the solar cells.Our study provides guidance on fabricating Sb2Se3thin film solar cell by the post low-deposition annealing process as the same structure as CIGS.Our findings suggest that the post low-deposition annealing process is a viable and competitive strategy to produce Sb2Se3 films and photovoltaic devices. |
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