Fig. 2: Charge capture and emission by defects in the insulator. | Nature Communications

Fig. 2: Charge capture and emission by defects in the insulator.

From: A standardized approach to characterize hysteresis in 2D-materials-based transistors for stability benchmarking and performance projection

Fig. 2: Charge capture and emission by defects in the insulator.The alternative text for this image may have been generated using AI.

a Single and double positively charged oxygen vacancies in Bi2SeO5. b Configuration-coordinate diagram illustrating electron capture within the non-radiative multi-phonon (NMP) framework. The potential energy in the two charge states is approximated by E1(Q) = c1Q2 and E2(Q) = c2(Q−ΔQ)2 + ΔE, where Q is the configuration coordinate. The capture and emission barriers ε12 and ε21 are governed by the coordinate shift ΔQ, the energy shift ΔE, the relaxation energy ER = c1ΔQ2 and the curvature ratio \(R=\sqrt{{c}_{1}/{c}_{2}}\). While ΔQ, ER, and R are defect specific, ΔE depends on the field-dependent alignment between the channel conduction band \({E}_{{{\rm{C}}}}^{{{\rm{ch}}}}\) and the effective charge-transition level \({E}_{{{\rm{T}}}}^{{{\rm{eff}}}}\) (see Supplementary Note 3). c Band diagram showing the conduction band EC, valence band EV, and the quasi-Fermi level \({E}_{{{\rm{F}}}}^{{{\rm{trap}}}}\), which transitions from the channel Fermi level \({E}_{{{\rm{F}}}}^{{{\rm{ch}}}}\) to the gate Fermi level \({E}_{{{\rm{F}}}}^{{{\rm{g}}}}\). In thermal equilibrium defects below \({E}_{{{\rm{F}}}}^{{{\rm{trap}}}}\) are predominantly occupied (blue circles), while those above are predominantly empty (white circles). d Conduction band \({E}_{{{\rm{C}}}}^{{{\rm{ch}}}}\), valence band \({E}_{{{\rm{V}}}}^{{{\rm{ch}}}}\) and Fermi level \({E}_{{{\rm{F}}}}^{{{\rm{ch}}}}({V}_{{{\rm{g}}}})\) of the channel. The Fermi level shifts from deep in the band gap at \({V}_{{{\rm{g}}}}={V}_{\min }\) toward the conduction band at \({V}_{{{\rm{g}}}}={V}_{\max }\). e Band diagram with the channel-sided active energy region highlighted in orange. The two horizontal dashed lines indicate \({E}_{{{\rm{F}}}}^{{{\rm{ch}}}}({V}_{\min })\) and \({E}_{{{\rm{F}}}}^{{{\rm{ch}}}}({V}_{\max })\). f Band diagram with the gate-sided active energy region highlighted in orange. The horizontal dashed line indicates \({E}_{{{\rm{F}}}}^{{{\rm{g}}}}\).

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