In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 59, No. 5 ( 2020-05-01), p. 051004-
Abstract:
We have observed negative Hall coefficients [ R H ( T )] in a nearest-neighbor hopping (NNH) conduction region in epilayers of heavily Al-doped or Al–N co-doped p-type 4H-SiC grown on n-type 4H-SiC substrates by CVD or in wafers of heavily Al–N co-doped p-type 4H-SiC fabricated by solution growth. We propose a simple physical model to explain the sign of R H ( T ) in NNH conduction. According to this model, R H ( T ) becomes positive when the Fermi level ( E F ) is higher than the Al acceptor level ( E Al ), that is, the Fermi–Dirac distribution function f ( E Al ) is greater than 0.5, whereas R H ( T ) becomes negative when E F is lower than E Al , which occurs at low temperatures. Because the dominant conduction mechanisms in heavily Al-doped or Al–N co-doped p-type 4H-SiC with Al concentrations on the order of 10 19 cm −3 are band and NNH conduction at high and low temperatures, respectively, the proposed model can explain why R H ( T ) becomes negative at low temperatures.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.35848/1347-4065/ab8701
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2020
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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