多晶硅太阳电池少子寿命的数值模拟

NUMERICAL SIMULATION ON MINORITY CARRIER LIFETIME FOR POLYCRYSTALLINE SILICON SOLAR CELLS

主要引入载流子的有效迁移率和有效扩散长度两个物理量,对多晶硅的少子寿命进行数值模拟。在此基础上建立了多晶硅太阳电池的一维物理模型,采用数值模拟方法对其在AM1.5太阳光入射下的电池输出特性J_(SC)、V_(OC)、FF和η进行模拟计算,着重分析了晶粒尺寸和基区少子寿命对多晶硅太阳电池性能的影响。模拟结果表明,晶粒尺寸和少子寿命是影响多晶硅太阳电池性能的两个关键因素。当少子寿命较低时,晶粒尺寸对电池效率的影响不大,此时电池效率的提高受限于少子寿命;当少子寿命增大时,电池效率随晶粒尺寸的增大显著提高。同时,从模拟结果可得到电池效率与少子寿命和晶粒尺寸之间的定量关系。

A physical model of polycrystalline silicon solar cells was presented. Using this model to study the effects of the grain size and minority carrier lifetime in base region on the four important properties Jac, Voc, FF and η by numerical simulation. Two physical quantities carrier effective mobility and effective diffusion length are used for the calculation. The results showed that grain size and minority carrier lifetime are two important effectors on the properties of polycrystalline silicon solar cells. There is little impact of grain size on efficiency when minority carrier lifetime is low, then the efficiency is influenced by minority carrier lifetime. When minority carrier lifetime is in- creased, the efficiency increased with the increasing of grain size. And from the simulation results, we can also get the quantitive relation between the efficiency, minority carrier lifetime and grain size. This will be a theoretical guide for the experiment of polycrystalline solar ceils made from materials by physical metallurgy, which has low mi- nority carrier lifetime or little grain size.