| 초록 |
In PERC(passivated emitter and rear cells), rear passivation is very important to obtain the high efficiency solar cell. To passivate the rear side of crystalline Si solar cell, Al2O3 layer was used and ALD(atomic layer deposition) was also used to deposit the Al2O3 layer on the rear side of Si wafer. Surface passivation is usually affected by a lot of factors, such as growth temperature, oxidant, and post-annealing etc. We examined surface passivation in the viewpoint of wafer cleaning, uniformity, carrier lifetime, thickness, negative fixed charge density at AlOx/Si interface, and reflectance. The influences of process temperature and heat treatment were also studied using Sinton WCT-120 equipment. Ozone-based ALD Al2O3 film shows the best carrier lifetime at lower deposition temperature than H2O-based ALD. |
