Abstract
This thesis is studying passivated silicon heterojunction solar cell by using aluminum oxide (AlOx) and plasma immersion ion implant (PIII). When aluminum oxide (AlOx) deposited on surface of wafer, the enhance electric field was produced near the surface of wafer, the enhance electric field can improve the mobility of carrier. Therefore, the trapping of carrier by dangling bond will be reduced. And by using plasma immersion ion implant (PIII), we can implant Nitrogen into the device to reduce dangling bond, then achieve passivation effect. Experiment 1, when we deposited AlOx on surface of solar cell, we can observe that short-circuit current density (Jsc), open-circuit voltage (Voc), and conversion efficiency (η) were increased from 27.84 mA/cm2, 5.52V, and 8.97% to 29.34 mA/cm2, 0.54V, and 9.68%. Experiment 2, we try to control the depth of Nitrogen by modulating different energy of PIII, and control the concentration of Nitrogen atoms by modulating different time of PIII. Finally, we obtained the best PIII condition is 2Kev 10minute. Finally, we use the best PIII condition (2Kev, 10min) to passivate heterojunction solar cell without AlOx passivation, then we have achieved the best solar cell conversion efficiency is 15.42%, Jsc is 37.78 mA/cm2, Voc of 0.55V and FF is 0.742.