Protocrystalline

A protocrystalline phase is a distinct phase occurring during crystal growth which evolves into a microcrystalline form. The term is typically associated with silicon films in optical applications such as solar cells.[1]

Crystallization
Fundamentals
Crystal · Crystal structure · Nucleation
Concepts
Crystallization · Crystal growth Recrystallization · Seed crystal Protocrystalline · Single crystal
Methods and technology
Boules Bridgman–Stockbarger method Crystal bar process Czochralski method Epitaxy · Flux method Fractional crystallization Fractional freezing Hydrothermal synthesis Kyropoulos method Laser-heated pedestal growth Micro-pulling-down Shaping processes in crystal growth Skull crucible Verneuil method Zone melting

Applications

Silicon solar cells

Amorphous silicon (a-Si) is a popular solar cell material owing to its low cost and ease of production. Owing to disordered structure (Urbach tail), its absorption extends to the energies below the band gap resulting in a wide-range spectral response; however, it has a relatively low solar cell efficiency. Protocrystalline Si (pc-Si:H) also has a relatively low absorption near the band gap owing to its more ordered crystalline structure. Thus, protocrystalline and amorphous silicon can be combined in a tandem solar cell where the top thin layer of a-Si:H absorbs short-wavelength light whereas the longer wavelengths are absorbed by the underlying protocrystalline silicon layer.[2]

See also

• Amorphous silicon
• Crystallite
• Multijunction
• Polycarbonate (PC)
• Polyethylene terephthalate (PET)

References

1. Ishikawa, Yasuaki; Schubert, Markus B. (2006-09-07). "Flexible Protocrystalline Silicon Solar Cells with Amorphous Buffer Layer". Japanese Journal of Applied Physics. 45 (9A): 6812–6822. doi:10.1143/jjap.45.6812. ISSN 0021-4922.
2. Ahn, Jun Yong; Jun, Kyung Hoon; Lim, Koeng Su; Konagai, Makoto (2003-03-10). "Stable protocrystalline silicon and unstable microcrystalline silicon at the onset of a microcrystalline regime". Applied Physics Letters. 82 (11): 1718–1720. Bibcode:2003ApPhL..82.1718A. doi:10.1063/1.1561161. ISSN 0003-6951.

External links

• Wilken, Karen (2017). "Low temperature thin-film silicon solar cells on flexible plastic substrates" (PDF). Advances in Systems Analysis. Forschungszentrum, Zentralbibliothek. 377. hdl:2128/14543. ISBN 978-3-95806-235-1. ISSN 1866-1793. OCLC 1075618416.