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Electrical characterization of metal–semiconductor–metal structure of pseudomorphic InGaN on GaN: Simulation and experiments
Author(s) -
Ohsawa Jun
Publication year - 2016
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.201533047
Subject(s) - ohmic contact , materials science , dark current , schottky barrier , schottky diode , optoelectronics , condensed matter physics , polarization (electrochemistry) , electrode , fermi level , semiconductor , layer (electronics) , nanotechnology , chemistry , diode , physics , quantum mechanics , photodetector , electron
Fermi level pinning at the free surface together with the Schottky barrier at the end electrodes forms a concave or convex lateral band structure at the surface of polarized nitrides. Experimental results on dark and photo current versus voltage characteristics as well as on responses to a short optical pulse revealed a concave structure for a 20‐nm thick InGaN layer with x = 0.13. A moderate polarization of 40% of a calculated value, a surface trap density of 2 × 10 13 /cm 2 located at 0.6 eV below E c , and a carrier lifetime of 1 ns can reproduce the experimental data. When Fermi level pinning is strong enough, a significant part of small bias voltages is bored by the surface InGaN layer, which results in an ohmic rise of the dark current.