The Effect of Al-BSF on S_eff and R_b in Industrialized Mono-Silicon Solar Cells

Abstract:

In this work, the effect of aluminum back surface field formed by screen printed various amount of Al paste on the effective rear surface recombination velocity (S_eff) and the internal rear reflectance coeffeicient (R_b) of commercial mono-silicon solar cells was investigated. We demonstrated the effect of S_eff and R_b on the performance of Al-BSF solar cells by simulating them with PC1D. The simulated results showed that the lower S_eff could get higher open circuit voltage (V_oc), at the same time, the larger R_b could get higher short-circuit current (I_sc). Experimentally, we investigated the S_eff and R_b through depositing Al paste with various amount (3.7, 5, 6, and 8 mg/cm²) for fabricating Al-BSF mono-silicon solar cells. Four group cells were characterized by light I-V, spectral response, hemispherical reflectance and scanning electron microscope (SEM) measurements. It was found that, a minimum S_eff of 350 cm/s was gotten from the cells with Al paste of 8 mg/cm², which was extracted by matching quantum efficiency (QE) from 800 nm to 1200 nm with PC1D, and a maximum R_b of 53.5% was obtained from Al paste of 5 mg/cm² by calculating at 1105 nm with PC1D. When the amount of Al paste was higher than 5mg/cm², there were less S_eff and lower R_b. On the other hand, when Al amount was 3.7mg/cm², it was too little to form a closed BSF. Based on the SEM graphs and simulations with PC1D, a simple explaination was proposed for the experimental results.

• Periodical: Advanced Materials Research (Volumes 472-475)
• Pages: 1846-1850
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.472-475.1846
• Online since: February 2012
• Authors: Shan Shan Dai, Gao Jie Zhang, Xiang Dong Luo, Jing Xiao Wang, Wen Jun Chen, Yue Ma
• Keywords: Al-BSF, R_b, S_eff, Silicon, Solar Cell

References

[1] J. Mandelkorn, J. H. Lamneck, in: 10th Photovoltaic Specialists Conference, 1973.

[2] Jerry G. Fossum, in: IEEE Transactions on Electron Devices, 1977, VOL.ED-24, No.4

[3] Paul A.Basore, in: IEEE Transactions on Electron Devices, VOL.37,NO.2, (1990)

[4] Martin Green: "Silicon solar cells advanced principles&practice", (1995)

[5] An-Ti Chai, in: IEEE 14th PVSEC, 1980, P156-160

[6] A.Goetzberger, in: IEEE 15th PVSEC, 1981, pp.867-870

[7] P.Lölgen and C.Leguijt, in: IEEE 23th PVSC, 1993, pp.236-242

[8] F. Huster, in: 20th EUPVSEC 2005, pp.1466-1469

[9] A.Ristow, M.Hilali, A.Ebong and A.Rohatgi, in: 17th EUPVSEC, (2001)

[10] P.Choulat, Y.Ma,BT.Chan, in: 23rd EUPVSEC, 2008, pp.1043-1047

[11] Paul A.Basore, in:IEEE 23th PVSC,1993, pp.147-152

[12] W.R. Runyan, "Semiconductor Mearsurements and Instrumentation", New York, (1975)

[13] Vichai Meemongkolkiat, Kenta Nakayashiki, in: IEEE ECS, 2006, pG53-G58

[14] Michael.P Godlewaki, in: IEEE 10th PVSC(1973), pp.40-49

[15] Armin G.Aberle, in: Progress in Photovoltaics: Research and Applications, 2000, pp.473-487