Study On Ti₃C₂T_x Mxene/Silicon Heterojunction Solar Cells

The current commercial solar cells are still dominated by traditional crystalline silicon（Si）solar cells,but its relatively high cost hinders its further promotion and application.In order to reduce the manufacturing cost of solar cells and take advantage of crystalline Si,researchers have developed transition metal oxide（TMO）/Si,carbon nanotube（CNT）/Si,PEDOT:PSS/Si and other dopant-free heterojunction crystalline Si solar cells in recent years.In order to broaden the types of dopant-free heterojunction crystalline Si solar cells,further reduce the manufacturing cost of solar cells and study the physical mechanism of novel structure solar cells,this paper studies a new type of dopant-free heterojunction crystalline Si solar cells:Ti₃C₂T_x MXene/n-Si heterojunction solar cell.The main work of this paper includes:（1）First,the Ti₃C₂T_x MXene material was successfully prepared by an optimized minimally intensive layer delamination（MILD）procedure,and then a variety of preparation methods were used to grow Ti₃C₂T_x film on the n-Si substrate to find a simple and efficient way to prepare Ti₃C₂T_x/n-Si heterojunction solar cells.The device was prepared by vacuum filtration-and-transfer（VFT）technique,interfacial film formation technique,and spin/drop casting methods.Finally,a variety of methods were used to prepare this new type of solar cell,which was experimentally verified to have Ag-grid/Ti₃C₂T_x/n-Si/In:Ga structure heterojunction solar cell structure and feasibility of preparation.After comprehensively evaluating the process difficulty of these preparation methods and the performance of the prepared devices,it is found that the drop casting method is a simple and effective method for preparing this new type of solar cell.（2）This novel type of solar cell based on Ti₃C₂T_x/n-Si heterojunction was prepared by a drop casting method,and the experimental parameters were optimized.First,the effect of using deionized water,absolute ethanol and dimethyl sulfoxide as the solvent of Ti₃C₂T_x on the preparation of devices was studied,and then the effect of the volume of the drop-casting Ti₃C₂T_x solution on the photoelectric properties of the prepared Ti₃C₂T_x film was determined.The factors affecting the performance of the device were analyzed,and finally a Ti₃C₂T_x/n-Si heterojunction solar cell with a power conversion efficiency（PCE）of 5.86%was prepared.The physical mechanism of this device was also studied.In order to improve the quality of the Ti₃C₂T_x film,an ethanol atmosphere is used to improve the drop casting process,which provides a stable environment for the evaporation of the drop cast Ti₃C₂T_x ethanol solution,prolongs the growth time of the Ti₃C₂T_x film,and makes the efficiency of the prepared solar cell reach 6.43%.In addition,the devices exhibit good stability after one week of exposure in the air at room temperature.