Abstract
Ion-implanted poly-crystalline silicon (poly-Si), in combination with a tunnel oxide layer, is investigated as a carrier-selective passivating contact in c-Si solar cells based on an interdigitated back contact (IBC) architecture. The optimized poly-Si passivating contacts enable low interface recombination, resulting in implied VOC (iVOC) of about 720 mV and 704 mV for n-type and p-type, respectively, before any hydrogenation step. It is found that high-quality passivation can be obtained when confining the dopants within the poly-Si layers and realizing a shallow diffusion of dopants into the c-Si bulk, meaning a sharp decrease in doping concentration in the c-Si at the poly-Si/c-Si interface. The doping profile at the poly-Si/c-Si interface can be influenced by poly-Si layer thickness, poly-Si ion-implantation parameters, and post-implantation annealing conditions. The detailed discussion on the passivation properties of the poly-Si passivating contacts and their preparation conditions are presented in this paper. In addition, IBC solar cells with/without front surface field (FSF) are fabricated, with the optimized poly-Si passivating contacts as back surface field, BSF (n-type poly-Si), and emitter (p-type poly-Si). The best cell shows an efficiency of 21.2% (VOC=692 mV, JSC=39.2 mA/cm2, FF=78.3%, and pFF=83.5%).
Original language | English |
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Pages (from-to) | 84-90 |
Number of pages | 7 |
Journal | Solar Energy Materials & Solar Cells |
Volume | 158 |
DOIs | |
Publication status | Published - 1 Dec 2016 |
Event | SiliconPV 2016: 6th International Conference on Silicon Phototvoltaics - Chambery, France Duration: 7 Mar 2016 → 9 Mar 2016 Conference number: 6 https://2016.siliconpv.com/home.html |
Keywords
- Ion-implantation
- Poly-silicon
- Passivating contact
- IBC c-Si solar cells