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Recent Progress in Understanding the Properties of the Amorphous Silicon/Crystalline Silicon Interface
Author(s) -
Kleider JeanPaul,
Alvarez José,
Brüggemann Rudolf,
GueunierFarret MarieEstelle
Publication year - 2019
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201800877
Subject(s) - heterojunction , materials science , crystalline silicon , silicon , amorphous silicon , amorphous solid , passivation , optoelectronics , nanocrystalline silicon , band offset , layer (electronics) , condensed matter physics , nanotechnology , band gap , crystallography , chemistry , valence band , physics
The authors review experimental and modeling approaches developed at GeePs to have a better knowledge and understanding of the interface between hydrogenated amorphous silicon (a‐Si:H) and crystalline silicon (c‐Si) in heterojunction solar cells. The authors emphasize the existence of a strong inversion layer at the c‐Si surface for both (n) a‐Si:H/(p) c‐Si and (p) a‐Si:H/(n) c‐Si heterojunctions. Conductive probe atomic force microscopy reveals the existence of a conductive channel at the c‐Si surface. The analysis of complementary lateral planar conductance and capacitance measurements allows for a better description of the band diagram in both types of heterojunctions especially through the determination of band offset values. Furthermore, the passivation properties of the (i) a‐Si:H buffer layer are studied by modeling the volume defects in a‐Si:H with the defect‐pool model. In particular, the DOS in the very thin (i) a‐Si:H layers is much larger than in bulk (i) a‐Si:H because the Fermi level position favors defect creation. Surface defects in c‐Si at the a‐Si:H/c‐Si interface are then quantified and the general trends of effective lifetime measurements with the (i) a‐Si:H layer thickness can be explained, notably the increase of the effective lifetime in c‐Si with increasing the (i) a‐Si:H buffer thickness.