Integration Processes for nPERT Si Solar Cells Using Single Side Emitter Epitaxy and front Side Laser Doping

Izabela Kuzma-Filipek, Maria Recaman-Payo, Yuandong Li, Ali Hajjiah, Filip Duerinckx, Emanuele Cornagliotti, Angel Uruena De Castro, Aashish Sharma, Tom Borgers, Richard Russell, Loic Tous, Joachim John (+3 others)
2015 Energy Procedia  
This work focuses on the fabrication of nPERT (Passivated Emitter, Rear Totally Diffused) devices incorporating an epitaxially grown single side rear-emitter. Such epi-nPERT cells are fabricated in a simplified way using the selectivity of the epitaxial deposition, which is obtained by a PECVD-SiOx layer, that not only mask the front but also passivates the cell. The cell performance is studied in terms of : i) various front surface fields (FSF) applied prior to emitter epitaxy and ii) usage of
more » ... laser doping as an alternative to laser ablation for a front contacting scheme. The results show: i) a clear relationship between the depth of the homogeneous FSF and its impact on the open circuit voltage of the devices, with a shallow FSF having the highest V OC loss due to laser damage and ii) laser doping on devices with a relatively deep diffused FSF giving 8mV increase in V OC as compared to devices with ablated dielectrics and a V OC increase of almost 30mV in case a shallow selective FSF is applied. This results in a best efficiency obtained so far for the epi nPERT devices of 21.6% (226cm 2 ).
doi:10.1016/j.egypro.2015.07.075 fatcat:g5zdietp35arrczqmqctux4vma