Pasanen, T.T.PasanenLaine, H.S.H.S.LaineVähänissi, V.V.VähänissiSchön, JonasJonasSchönSavin, HeleHeleSavin2022-03-052022-03-052018https://publica.fraunhofer.de/handle/publica/25176210.1038/s41598-018-20494-yBlack silicon (b-Si) is currently being adopted by several fields of technology, and its potential has already been demonstrated in various applications. We show here that the increased surface area of b-Si, which has generally been considered as a drawback e.g. in applications that require efficient surface passivation, can be used as an advantage: it enhances gettering of deleterious metal impurities. We demonstrate experimentally that interstitial iron concentration in intentionally contaminated silicon wafers reduces from 1.7 × 1013 cm−3 to less than 1010 cm−3 via b-Si gettering coupled with phosphorus diffusion from a POCl3 source. Simultaneously, the minority carrier lifetime increases from less than 2 ms of a contaminated wafer to more than 1.5 ms. A series of different low temperature anneals suggests segregation into the phosphorus-doped layer to be the main gettering mechanism, a notion which paves the way of adopting these results into predictive process simulators. This conclusion is supported by simulations which show that the b-Si needles are entirely heavily-doped with phosphorus after a typical POCl3 diffusion process, promoting iron segregation. Potential benefits of enhanced gettering by b-Si include the possibility to use lower quality silicon in high-efficiency photovoltaic devices.enSolarzellen - Entwicklung und CharakterisierungPhotovoltaikSilicium-PhotovoltaikCharakterisierung von Prozess- und Silicium-MaterialienDotierung und Diffusionjournal article