Analysis of Random telegraph noise in large-area amorphous double-barrier structures

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Details zur Publikation

Autor(en): Hundhausen M, Ley L
Zeitschrift: Physical Review B
Verlag: American Physical Society
Jahr der Veröffentlichung: 1993
Band: 47
Seitenbereich: 12687
ISSN: 0163-1829


Abstract

We have measured the temporal behavior of the perpendicular current through large-area (0.25 mm2) double-barrier structures fabricated from n+-type a-Si:H and quasistoichiometric a-SiNx:H. The current switches randomly between distinct values with an amplitude between 0.5% and 10% of the total current. This behavior is reminiscent of random telegraph noise (RTN) observed in small-area (<1 μm2) devices. The power spectra of the RTN can be fitted by a superposition of Lorentzians from which effective switching rates can be deduced. They are thermally activated and exhibit a dependence on the voltage applied to the sample. The RTN switching can be influenced optically by illuminating the sample surface with a He-Ne laser. While scanning the device area with the focused laser the RTN is influenced at one well-defined spot only. We associate this spot with a filament of less than 1 μm2 in size that carries a large fraction of the current through the device and argue that the current is controlled by the charging and discharging of a single defect in proximity to this filament via Coulomb blocking resulting in the observed RTN. In different samples distributions of switching times for capture and emission of electrons at a single defect are measured as a function of applied voltage and temperature. Based on these data different configurations of the defect located in the nitride barrier are discussed within a model of an acceptorlike trap with a strong electron-lattice coupling which exchanges charge with the adjacent n+-type a-Si:H layers. © 1993 The American Physical Society.


FAU-Autoren / FAU-Herausgeber

Hundhausen, Martin apl. Prof. Dr.
Lehrstuhl für Laserphysik
Ley, Lothar Prof. Dr.
Naturwissenschaftliche Fakultät

Zuletzt aktualisiert 2018-09-08 um 04:54