直拉硅单晶热处理及其对太阳电池性能的影响

The Heat Treatment of CZ-Si Single Crystals and Its Effect on Solar Cell Characteristics

研究了直拉头尾料P型硅单晶片在360～1 300℃范围热处理前后氧碳含量、电阻率和少子扩散长度的变化规律及其对所制成太阳电池性能的影响。已证实在最佳的热处理条件下样品含氧量减少,少子扩散长度和电池效率达到最大,比未作热处理的单晶电池效率提高0.5～2倍,为利用这类单晶提供了有效方法。对此现象用热施主与深中心相互作用的模型作了初步解释。

Variations of oxygen and carbon contents, resistivity and minority carrier dif-fusion length caused by heat treatment from 360 to 1300 in P-type CZ-Si single crys-tal made from head and end materials and effect of the variations on characteristics of Si so-lar cell are studied. It is verified that under optimum heat treatment conditions, oxygen content decreases, minority carrier diffusion length and relevant solar cell efficiency come up to maxima. As compared with the normal solar cells,these solar cell efficiencies increase by a factor of 0. 5-2. 0. It will possibly provide an effective method for using these Si single crystals. A model of interaction between heat donor and deep centres is developed, and it is used to explaine above-mentioned phenomenons.