TY - JOUR
T1 - Hydrogen-Assisted Defect Engineering of Doped Poly-Si Films for Passivating Contact Solar Cells
AU - Truong, Thien N.
AU - Yan, Di
AU - Samundsett, Christian
AU - Liu, Anyao
AU - Harvey, Steven P.
AU - Young, Matthew
AU - Ding, Zetao
AU - Tebyetekerwa, Mike
AU - Kremer, Felipe
AU - Al-Jassim, Mowafak
AU - Cuevas, Andres
AU - MacDonald, Daniel
AU - Nguyen, Hieu T.
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/12/23
Y1 - 2019/12/23
N2 - Hydrogen-assisted defect engineering, via a hydrogenated silicon nitride (SiNx:H) capping layer, on doped polycrystalline silicon (poly-Si) passivating-contact structures, is explored using complementary techniques. The hydrogen treatment universally improves the passivation quality of poly-Si/SiOx stacks on all samples investigated. Meanwhile, their contact resistivity remains very low at ∼6 mω·cm2. Moreover, the nature of charge carrier recombination within the poly-Si films is also investigated by means of photoluminescence. On planar c-Si substrates, the poly-Si films emit two broad photoluminescence peaks at ∼850-1050 and ∼1300-1500 nm. The former is the characteristic peak of the hydrogenated amorphous Si (a-Si:H) phase and only appears after the treatment, demonstrating that (i) a significant amount of hydrogen has been driven into the poly-Si film and (ii) an amorphous phase is present within it. The second peak originates from sub-band-gap radiative defects inside the poly-Si films and increases after the treatment, suggesting a suppression of their nonradiative recombination channels. For films deposited on textured c-Si substrates, there is a disrupted oxide boundary, preventing a buildup of excess carriers inside the films and leading to quenching of the film luminescence.
AB - Hydrogen-assisted defect engineering, via a hydrogenated silicon nitride (SiNx:H) capping layer, on doped polycrystalline silicon (poly-Si) passivating-contact structures, is explored using complementary techniques. The hydrogen treatment universally improves the passivation quality of poly-Si/SiOx stacks on all samples investigated. Meanwhile, their contact resistivity remains very low at ∼6 mω·cm2. Moreover, the nature of charge carrier recombination within the poly-Si films is also investigated by means of photoluminescence. On planar c-Si substrates, the poly-Si films emit two broad photoluminescence peaks at ∼850-1050 and ∼1300-1500 nm. The former is the characteristic peak of the hydrogenated amorphous Si (a-Si:H) phase and only appears after the treatment, demonstrating that (i) a significant amount of hydrogen has been driven into the poly-Si film and (ii) an amorphous phase is present within it. The second peak originates from sub-band-gap radiative defects inside the poly-Si films and increases after the treatment, suggesting a suppression of their nonradiative recombination channels. For films deposited on textured c-Si substrates, there is a disrupted oxide boundary, preventing a buildup of excess carriers inside the films and leading to quenching of the film luminescence.
KW - amorphous silicon
KW - doped polycrystalline silicon
KW - hydrogenation
KW - passivating contacts
KW - photoluminescence
UR - http://www.scopus.com/inward/record.url?scp=85076730175&partnerID=8YFLogxK
U2 - 10.1021/acsaem.9b01771
DO - 10.1021/acsaem.9b01771
M3 - Article
SN - 2574-0962
VL - 2
SP - 8783
EP - 8791
JO - ACS Applied Energy Materials
JF - ACS Applied Energy Materials
IS - 12
ER -