Ultra-narrow strip-shaped silicon solar cells for semi-transparent PV modules: Interplay among cut edges, cell structure, strip dimensions, and partial edge passivation

Ultra-narrow strip-shaped crystalline silicon (c-Si) solar cells are promising for translucent photovoltaic modules but suffer from significant efficiency losses due to edge recombination after cell separation. An additional edge passivation process can alleviate this loss, but it increases cost and process complexity. This study investigates alternative approaches to suppress edge recombination loss without dedicated passivation layers. Strip-shaped silicon heterojunction (SHJ) cells, 3–9 mm wide, were fabricated using laser scribing and mechanical cleaving (LSMC). Experimental results, supported by device simulations, reveal that front-junction configurations and thinner c-Si substrates effectively mitigate efficiency loss associated with cut edges. Two additional design strategies were evaluated. A transparent conductive oxide (TCO) margin approach, which removes the emitter near the edge, improved open-circuit voltage to 715 mV in 5-mm-wide cells, although efficiency was constrained by reduced short-circuit current density. In contrast, the Pre-Grooved LSMC (PG-LSMC) method, enabling in-situ partial edge passivation, suppressed edge recombination and enhanced efficiency, particularly in rear-junction-type cells. These results highlight that optimized device design, thickness reduction, emitter isolation, and in-situ partial passivation can compensate for the absence of dedicated edge passivation. The insights gained from these extreme geometries are broadly applicable to divided and shingled cells, where edge recombination remains a critical loss mechanism. • Front-junction design and thinner substrates reduce edge-related loss in ultra-narrow cells. • TCO margin approach mitigates V OC & FF losses in ultra-narrow cells. • Pre-grooved LSMC method enables in-situ partial edge passivation, enhancing cell efficiency. • The above-mentioned strategies compensate for the absence of dedicated edge passivation.