Phosphorus emitter engineering by plasma-immersion ion implantation for c-Si solar cells

• Published in: Solar energy materials and solar cells Vol. 133; pp. 194 - 200
• Main Authors: Michel, Thomas, Le Perchec, Jérôme, Lanterne, Adeline, Monna, Rémi, Torregrosa, Frank, Roux, Laurent, Commandré, Mireille
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-02-2015; Elsevier
• Subjects: Aluminum; Crystalline silicon; Doping; Double layer; Electric power; Emittance; Engineering Sciences; INES (sat nav sys); Ion implantation; Materials; Micro and nanotechnologies; Microelectronics; Optics; Photonic; Photovoltaic cells; Photovoltaics; Plasma-immersion; Solar cell; Solar cells; Solar energy; Solar cell; Ion implantation; Crystalline silicon; Plasma-immersion; Photovoltaics
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2014.11.014

Ion Beam Services (IBS) has developed processes dedicated to silicon-based solar cell manufacturing using a plasma-immersion ion implantation equipment. It enables the realization of various doping profiles for phosphorus-doped emitters which fit the requirements of high-efficiency solar cells. PH3 plasma-implanted emitters are chemically, physically and electrically characterized to demonstrate their excellent quality. Those emitters are then integrated into a low cost p-type monocrystalline silicon solar cell manufacturing line from the National Solar Energy Institute (INES) in order to be compared with usual POCl3 diffusion. Starting from a basic process flow with blanket emitter and conventional full-area aluminum back-surface field, plasma-immersion implanted emitters enable to raise conversion efficiencies above 19.1%. Thanks to an optimized double layer anti-reflective coating, a 19.4% champion cell has been achieved. Depending on different plasma process parameters, lightly doped emitters are then engineered aiming to study doping modulation using a dedicated laser.
•Plasma-immersion ion implantation of PH3 for n-type emitter on Cz–Si.•Annealing enables solid-phase epitaxial regrowth and SiO2 emitter passivation.•19.4% champion cell achieved on p-type 239cm2 Cz–Si solar cell with full Al-BSF.•Phosphorus doping profiles are easily tunable for selective emitter fabrication.