Si-rich SiNx rear passivated c-Si solar cell with a novel antimony Local Back Surface Field formed by Laser Fired Contact

• Antimony doped Local Back Surface Field created with Laser Fired Contact process.
• Si-rich SiNx (n = 2.7) with lifetime (2 ms) is applied for rear surface passivation.
• With optimized Sb thickness and improved rear surface passivation, Voc increased.
• Sb LBSF cell yielded a Voc of 643 mV and efficiency of 19.25%.
• .25%, compared to the reference cell with Voc of 625 mV and efficiency of 18.20%.

Local Back Contact (LBC) crystalline silicon solar cell with novel antimony (Sb) Local Back Surface Field (LBSF) are reported. The Sb LBSF is formed at low temperature with a Laser Fired Contacts (LFC) process. To improve the solar cell parameters of Sb LBSF, the rear passivation layer with SiNx is optimized by varying the refractive index. The Si-rich SiNx with a refractive index (n) of 2.7 possesses high lifetime of 2 ms with reduced absorption at a longer wavelength. The increase in lifetime is analyzed with Si–H bond concentration by FTIR. A 100 nm thick Sb layer with low laser power of 44 mW resulted in a junction depth of 500 nm with a carrier concentration of 5 × 1020 cm−3. The improved rear passivation with Si-rich SiNx, the optimized Sb thickness yielded the best electrical results, with open circuit voltage (Voc) of 643 mV and efficiency of 19.25%, compared to the reference cell with Voc of 625 mV and efficiency of 18.20%.