Photoassisted tunneling from free-standing GaAs thin films into metallic surfaces

Physical Review B - Condensed Matter and Materials Physics

Volumn 82, Issue 11, 2010, Pages

  Vu, D ^a   Arscott, S ^b   Peytavit, E ^b   Ramdani, R ^c,d   Gil, E ^c,d   Andre Y ^c,d   Bansropun, S ^e   Gerard B ^f   Rowe, A C H ^a   Paget, D ^a  

^a LABORATOIRE DE PHYSIQUE DE LA MATIÈRE CONDENSÉE   (France)

^b UNIV LILLE   (France)

^c UNIVERSITÉ CLERMONT AUVERGNE   (France)

^d CNRS   (France)

^e THALES RESEARCH AND TECHNOLOGY   (France)

^f ALCATEL THALES III V LAB   (France)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 77957572227     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.82.115331     Document Type: Article

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40. This approach neglects the tunnel current from the valence band J t v. At short distance, the semiconductor band structure follows the motion of the metal Fermi level (V s = V) so that J t v = 0 since valence-band states lie below the metal Fermi level. At large distance, one would expect in the same way as in Fig., appearance of J t v at a bias on the order of - 0.6 V. Such effect is not observed experimentally, probably because of the smallness of the tunnel matrix element or of the coherence length in the valence band which as seen in Eq. appears in the two-dimensional density of states in the valence band.
41. 0 have not been taken into account under light excitation. This is reasonable since (i) photoelectron capture processes increase the kinetics of establishment of equilibrium with the semiconductor, (ii) because of the photovoltage, the correction term, proportional to Δ φ - q V s is smaller under light excitation than in the dark.