Thermally grown SiOx interlayers for stabilizing interfacial passivation in AlOx/SiOx/Si structures for high-efficiency solar cells

초록

The thermal robustness of aluminum oxide (AlOx) passivation used in crystalline silicon solar cells is often limited under annealing, SiNx deposition, and metallization firing. Although interfacial silicon oxide (SiOx) improves the robustness of AlOx passivation, the mechanisms underlying this improvement remain unclear. In this study, we investigated the influence of interfacial SiOx layers on the quality and thermal robustness of AlOx passivation on crystalline silicon solar cells. Two SiOx interlayers were considered: the first was intentionally grown thermal SiOx prior to atomic layer deposition (ALD) of AlOx, and the second was SiOx formed spontaneously during the annealing subsequent to the AlOx layer deposition. The intentionally-grown SiOx interlayer maintained excellent passivation and exhibited superior thermal stability compared to the spontaneously-formed SiOx interlayer owing to its more oxidized silicon surface and thermodynamically stable structural phase. This dual effect provides practical guidance for process optimization to achieve higher efficiency and durability in silicon photovoltaics.

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