Local Edge Passivation of Laser Scribed Shingle Cells for Compensating Cut Losses
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Author
Sah, Dheeraj
Parfeniukas, Karolis
Boccardi, Roberto
Bandaru, Narendra
Lachowicz, Agata
Borie, Benjamin
Baraket, Mira
Plakhotnyuk, Maksym
dos Reis Benatto, Gisele A.
Thorsteinsson, Sune
DOI
Abstract
Crystalline silicon based solar cells have set a new benchmark for the highest efficiencies ever achieved for single junction solar cells. In recent times, LONGi [1] and Trina Solar [2] posted efficiencies > 27% for heterojunction back contact (HBC) and half cut heterojunction thin film (HJT) solar cells. Recent results by Trina Solar also showcased efficiencies > 26.5% for tunnel oxide passivated contact (TOPCon) cells [2]. Even though high efficiencies are achieved for solar cells, the highest efficiency obtained at module level is 24.9%. Multiple factors like transmission losses of incident light through glass and encapsulating layer, shading from bus bars, connecting wires, inactive area between cells in conventional modules, and the resistive losses due to increased current contribute to the power losses at module level. To reduce resistive losses in the module, the industry is cutting cells into half, into thirds and even using shingling interconnection where even smaller bits are used. Cutting the solar cells results in new recombination sites at the edges and thereby decreased cell performance. To mitigate these losses, it is important to analyze the cut edges and develop passivation strategies to recover the cell parameters. Herein, we try to passivate the cut edges locally through Direct Atomic Layer Processing (DALP) using the Nanofabricator tool developed by ATLANT 3D. With this tool we are able to locally deposit different materials, TiO2 in this work, along the edges of the laser scribed cell pieces. The results after passivation show improvements of 2.1 mV and 0.30% for implied open circuit voltage (iVoc) and fill factor (iFF), respectively.
Publication Reference
EUPVSEC 2025, Bilbao, Spain
Year
2025