Bifacial shingle solar cells on p-type Cz-Si (pSPEER)

Abstract

Abstract. The concepts of bifaciality and shingling interconnection allow for a boost in output power density pout for silicon-based photovoltaic modules. This work examines silicon-based, bifacial shingle solar cells called "p-type shingled passivated edge, emitter, and rear (pSPEER)". A specially designed shingle metallization layout on industrial 6-inch p-type Czochralski-grown silicon precursors is contact fired to obtain the host wafer. Six pSPEER cells each of an area of 23 mm x 148 mm are obtained by a newly integrated thermal laser separation step, leaving a very smooth edge for the singulated pSPEER cells. The peak front side output power density is pout,f = 20.8 mW/cm 2 (equivalent to a peak energy conversion efficiency  = 20.8% under standard test conditions). A total output power density pout = 21.9 mW/cm 2 is attained by assuming an additional rear irradiance of 100 W/m².

How to assess the electrical quality of solar cell interconnection in shingle solar modules

“…After presenting experimental results for R int for two different ECAs in the previous section, the simulations in Section 3. and Balioziant et al 12 C and ECA D in terms of CTM loss according to Figure 3. On an industrial production level, a discrepancy of ΔR int = 4 mΩ would thus be highly relevant.…”

“…Finally, a new approach to experimentally determine R int by evaluating the dark I-V curve of three-shingle-stings is tested. In a first step, gallium-doped monofacial monocrystalline silicon G1 PERC shingle host cells fabricated in mass production are separated by a laser scribe and mechanical cleaving (LSMC) 12,23 process. Form the thereby obtained shingles, only the middle pieces that are full square shingles with nominal size A shingle = (158.75 Á 31.75) mm 2 are taken.…”

“…For this, an industrial cell tester is used that fixes the shingles by four pin arrays (on each shingle edge, one pin array comes from the top and one from the bottom). 12 Of course, only the pin arrays placed on the busbars are used for electrically contacting the shingles (the other ones serve just for fixing the shingles).…”

“…10 For an overview on the shingling technology, please refer to other works. [4][5][6][7][8][9]11,12 This work focuses on the electrical quality of shingle joints and omit all other aspects of the shingling technology such as the mechanical properties of shingle joints.…”

TOPCon shingle solar cells: Thermal laser separation and passivated edge technology

“…In 2019, Fraunhofer ISE introduced the post-metallization passivated edge technology (PET) and demonstrated edge passivation on PERC shingle cells. 7,26 The PET consists of the deposition of a passivation layer after cell separation, for example, an aluminum oxide (Al 2 O 3 ) layer-which is known for excellent passivation quality 27 -with subsequent activation of the same by means of elevated temperature exposure, also referred to as annealing.…”