Optimized Interconnection of Passivated Emitter and Rear Cells by Experimentally Verified Modeling

The impact of silicon solar cell architecture and cell interconnection on energy yield in hot & sunny climates

“…These findings are generally valid for silicon solar cells and not limited to a specific absorber material. The strategy to reduce ohmic losses on the module level using a high R MPP (high voltage, low current) is also reflected in the approach of using half-cells for module fabrication 61 . However, this is only beneficial if the metallization of the cells is designed as if they were full-cells.…”

Optimized front TCO and metal grid electrode for module‐integrated perovskite–silicon tandem solar cells

“…, where R lateral S denotes the lateral series resistance arising from front TCO and top cell; and R finger S denotes the series resistance due to the metal fingers, which are both obtained using Quokka3. 20 The series resistance of the multi-wire interconnection R wires S is calculated according to Witteck et al 21 and Goetzberger et al 22 assuming copper wires with a diameter of 350 μm. 23 Subsequently, we calculate the internal power P int ¼ V mpp,int Á j mpp of the Pero-Si tandem device, which does not include the electrical losses of the front TCO and grid electrode, but which incorporates the parasitic absorption losses of the optical TCAD model (especially of the front TCO) and includes shading losses of the metal fingers and multi-wires (with optical width of 210 μm due to back reflection of the round wires according to Witteck et al 21 The j mpp is based on the assumptions according to Messmer et al 9 using the optical generation current from the TCAD model.…”

“…20 The series resistance of the multi-wire interconnection R wires S is calculated according to Witteck et al 21 and Goetzberger et al 22 assuming copper wires with a diameter of 350 μm. 23 Subsequently, we calculate the internal power P int ¼ V mpp,int Á j mpp of the Pero-Si tandem device, which does not include the electrical losses of the front TCO and grid electrode, but which incorporates the parasitic absorption losses of the optical TCAD model (especially of the front TCO) and includes shading losses of the metal fingers and multi-wires (with optical width of 210 μm due to back reflection of the round wires according to Witteck et al 21 The j mpp is based on the assumptions according to Messmer et al 9 using the optical generation current from the TCAD model. For the internal voltage at MPP, we assume a constant value of V mpp,int ¼ 1.6 V, of which we attribute 960 mV to the perovskite top cell (with the improved electrical properties according to Schulze et al 8 ) and 642 mV to the SHJ bottom cell (at half a sun!).…”

“…To be comparable, both parts (A) and (B) are for a M6 wafer with 9 wire interconnection 350 μm and an optical width of 210 μm due to back-reflection on the round wires. 21 Starting with 18 wires, we compare the different finger metallization types. Figure 4 shows the cell efficiency within the module stack (i.e., P out of Equation 1) for a silver screen printing paste as used for the SHJ baseline process (red, 220 C) which is, however, (currently) not applicable on a perovskite top cell.…”

“…One can see the internal power P int according to Equation 1 (Figure3A, grey diamonds) as a function of the ITO thickness (varied from 75 to 10 nm), the ITO oxygen flow (increasing O 2 content from 'ITO1' to 'ITO4') and front finger pitch (varied from 1 to 2.5 mm within each segment). P int lumps the optical effects of the transparency of the ITO and the shading of the front metallization (where the optical finger width is 50% of the geometrical finger width in the module) 21,24. Therefore, P int is increased from left to right for using more transparent and thinner ITOs and increased front finger pitch, i.e.…”