V2O5–B2O3金属氧化物玻璃对背钝化电池局域铝背场性能的影响

Impact of V2O5–B2O3 Metal Oxide Glass Frits on Local Aluminum Back Surface Field of Passivated Emitter and Rear Contact Cell

采用不同V2O5–B2O3比例的金属氧化物玻璃粉(V–B–MO)制备了背钝化硅太阳能电池(PERC),对电池进行了电性能、扫描电子显微镜和电池电致发光(EL)等测试分析。对玻璃粉进行了热分析,研究了V–B–MO玻璃粉对PERC电池局域铝背场性能的影响。结果表明:当玻璃的V–B比例在质量比为25:35的情况下,电池有较高的开路电压和转换效率。通过对V–B–MO玻璃添加稀土元素氧化物La2O3,CeO2等,可提高电池的电性能。玻璃的相变温度、熔化温区和熔化吸热量等热特性对局域铝背场的形成及填充率有直接的影响,熔点较低、熔化温区较窄的玻璃制作的电池有较好的光电转换效率。局域铝背场处存在完全填充、部分填充和没有填充3种状态,填充较差部位会在EL图像中产生黑线。

The passivated emitter and rear contact(PERC) silicon solar cells were prepared by using V2O5–B2O3 metal oxide(V–B–MO) glass frit at different V2O5–B2O3 ratios. The cells were analyzed by electrical properties test, scanning electron microscopy and electroluminescent(EL) measurement. The effect of V–B–MO glass frit on the local aluminum back surface ?eld performance of the PERC cells was investigated via thermal analysis. The results show that the cells have higher open circuit voltage and conversion efficiency when the V–B mass ratio of glass is 25:35. The electrical performance of the cells can be improved when the rare-earth element oxides such as La2O3, CeO2, etc. are added to V–B–MO glass. The thermal characteristics of glass(i.e., phase transition temperature, melting temperature zone and melting heat absorption) have a direct impact on the formation of local aluminum back surface field and filling rate. Besides, the cells made of glass with a low melting point and a narrow melting temperature zone have a better photoelectric conversion efficiency of cells. There are three states at the local aluminum back surface field, i.e., full filling, partial filling and no filling. The black line appears in the EL image when the filling is poor.