Wafer-thickness Dependence of Double-side Contacted Rear Junction n-type Solar Cells

We investigate the wafer-thickness dependence of double-side contacted rear junction n-type solar cells, theoretically by PC1D simulations and experimentally. To get the correct input parameters for PC1D, we first fit PC1D simulation to a rear junction cell fabrication of a complete ingot. The simulated cell performance of thin cells is mainly influenced by short circuit current Jsc. For wafer-thickness < 100 μm, light trapping becomes challenging and causes a steep decline in Jsc. This Jsc loss can also be seen in an IQE drop at long wavelengths of fabricated thin cells. For wafer-thickness > 100 μm, only minor variation in efficiency is predicted by simulation, which makes the cell concept suitable for 100 to 200 μm thick wafers. Median cell efficiencies of 20% for 100 μm thin- 6” Cz Si cells are reported.