The Preparation Of Black Silicon Material And The Research Of Battery Performance

It is found that the black silicon with textural structure has high absorption and low reflectance to the incident sunlight in a wide wavelength range.This reduces the effect of spectral mismatches between sunlight and silicon wafers on the efficiency of solar cells.This technology has great applications in improving the efficiency of solar cells.The microstructure change of black silicon and its effect on solar reflectance under different corrosion conditions and processes were studied by using metal-assisted chemical corrosion method.The corrosion principle was analyzed and the reflectance and surface profile of the corroded silicon wafer were characterized.The results showed that silver nitrate was used as the active site,hydrogen fluoride as the oxidant and hydrogen peroxide as the corrosive agent.With the help of ultrasound,p-type polysilicon was corroded and black silicon was finally obtained.Based on different process(silicon wafer cutting way,ultrasonic,corrosion time)under the condition of black silicon surface morphology were characterized,and study the influence of the weave structure of black silicon reflectivity,found that with gold thread cutting silicon corrosion under the conditions of ultrasonic 60 s,silicon wafer surface weave structure length is about 1 ?m,at this point in the 300 nm to 1100 nm wavelength range,the black silicon minimum reflectivity of 2.6 %.The main reason is that as the active site,silver particles accelerate the longitudinal corrosion rate of the silicon wafer.At this time,the notch structure generated on the surface of the silicon wafer is conducive to the secondary reflection of incident sunlight,which greatly reduces the reflectivity and increases the short-circuit current density of the battery,which is conducive to the improvement of efficiency.At present,the preparation of PN junction takes phosphorus tricloxate as the phosphorus source.This method has high requirements for equipment,takes a long time,and the raw material is highly toxic,causing serious environmental pollution.Based on the principle of phosphorus,this topic is chosen as a source of phosphorus,phosphate facilitation processing scheme of annealing equipment,and through to the process of annealing temperature,time,etc,it is concluded that when the concentration of phosphorus source was 5 %,the annealing temperature is 900 ?,annealing time for 5 min,black silicon slice of the photoelectric conversion efficiency is the highest 10.5 %,compared with the original silicon wafer in terms of the efficiency of 9.6 %,the efficiency increased by 9.4%.The main reason is that under this condition,the black silicon cell has a good quality of PN junction,effectively reduces the carrier recombination rate,and has a low square resistance value,so that the value of filling factor is improved,which effectively improves the photoelectric conversion efficiency of the cell.