We investigated the possible application of molybdenum oxide (MoOx) on the backside of p-type SHJ solar cells as substitute for the silicon-based back surface field layer. Solar cells with 4 cm2 area were fabricated on FZ c-Si(p) <100> wafers, passivated with ultrathin i-a-Si:H buffers. A nanocrystalline n-SiOx emitter was applied while on the backside we applied 20 nm-thick p-type a-Si:H or evaporated MoOx (10 nm). Symmetric samples were additionally prepared to compare the effects on wafer passivation of MoOx versus the more conventional p-a-Si:H layer. For flat devices we have observed a Voc increase of ∼40 mV with MoOx replacing p-a-Si:H, with fill factors ∼73% in both the cases. Globally an efficiency increase of 1% absolute has been achieved moving to the MoOx hole collector. The feasibility of the MoOx/Ag backside configuration has been demonstrated also for textured p-type SHJ solar cells, reaching so far an efficiency of 18.1%. © 2018 Author(s).
MoOx as hole-selective collector in p-type Si heterojunction solar cells
Lancellotti, L.;Bobeico, E.;Usatii, I.;Mercaldo, L.V.
2018-01-01
Abstract
We investigated the possible application of molybdenum oxide (MoOx) on the backside of p-type SHJ solar cells as substitute for the silicon-based back surface field layer. Solar cells with 4 cm2 area were fabricated on FZ c-Si(p) <100> wafers, passivated with ultrathin i-a-Si:H buffers. A nanocrystalline n-SiOx emitter was applied while on the backside we applied 20 nm-thick p-type a-Si:H or evaporated MoOx (10 nm). Symmetric samples were additionally prepared to compare the effects on wafer passivation of MoOx versus the more conventional p-a-Si:H layer. For flat devices we have observed a Voc increase of ∼40 mV with MoOx replacing p-a-Si:H, with fill factors ∼73% in both the cases. Globally an efficiency increase of 1% absolute has been achieved moving to the MoOx hole collector. The feasibility of the MoOx/Ag backside configuration has been demonstrated also for textured p-type SHJ solar cells, reaching so far an efficiency of 18.1%. © 2018 Author(s).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
