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 x 10(20) cm(-3). The improved rear passivation with Si-rich SiNx, the optimized Sb thickness yielded the best electrical results, with open circuit voltage (V-oc) of 643 mV and efficiency of 19.25%, compared to the reference cell with V-oc of 625 mV and efficiency of 18.20%. (C) 2013 Elsevier B. V. All rights reserved.