Clarifying the high on/off ratio mechanism of nanowire UV photodetector by characterizing surface barrier height

Nanoscale ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 2242-2248 ◽  
Author(s):  
Gaoda Li ◽  
Leixin Meng ◽  
Xiaofei Zhu ◽  
Weihao Gao ◽  
Yong Qin ◽  
...  
Keyword(s):  
Space Charge ◽  
Barrier Height ◽  
Surface Potential ◽  
Surface Barrier ◽  
Zno Nanowire ◽  
Uv Photodetector ◽  
Potential Measurement ◽  
Charge Model ◽  
Space Charge Model

The high on/off ratio mechanism of ZnO nanowire UV photodetector is clarified by calibrated surface potential measurement and space charge model.

scholarly journals Modelling the Ionic Conductivity of Nanopores with Electrically Conductive Surface

2021 ◽  
pp. 74-86
Author(s):  
Artur I. Krom ◽  
Maria I. Medvedeva ◽  
Ilya I. Ryzhkov
Keyword(s):  
Ionic Conductivity ◽  
Space Charge ◽  
Surface Potential ◽  
Debye Length ◽  
Ion Concentration ◽  
Electrically Conductive ◽  
Conductive Surface ◽  
Charge Model ◽  
1D Model ◽  
Space Charge Model

The ionic conductivity of nanopores with electrically conductive surface is investigated theoretically. The generalization of two-dimensional (2D) Space–charge model to calculating the ion transport under the applied potential gradient in a nanopore with constant surface potential is proposed for the first time. The results are compared with one-dimensional (1D) Uniform potential model, which is derived from the Space–charge model by assuming the independence of potential, ion concentrations, and pressure on the radial coordinate. We have found that the increase of surface potential magnitude leads to the enhancement of conductivity due to the increase of counter–ion concentration inside the nanopore. It is shown that the 1D and 2D models provide close results when the pore radius is smaller than the Debye length. Otherwise, the 1D model essentially overestimates the ionic conductivity. According to the 2D model, the ionic conductivity decreases with increasing the nanopore radius, while the 1D model predicts the opposite trend, which is not physically correct

An application of the space charge model to the electrolyte conductivity inside a charged microporous membrane

1999 ◽  
Vol 161 (1-2) ◽  
pp. 275-285 ◽  
Author(s):  
Anthony Szymczyk ◽  
P. Fievet ◽  
B. Aoubiza ◽  
C. Simon ◽  
J. Pagetti
Keyword(s):  
Space Charge ◽  
Microporous Membrane ◽  
Electrolyte Conductivity ◽  
Charge Model ◽  
Space Charge Model

scholarly journals The quantum zero space charge model for semiconductors

1999 ◽  
Vol 10 (4) ◽  
pp. 395-415 ◽  
Author(s):  
A. UNTERREITER
Keyword(s):  
Space Charge ◽  
Debye Length ◽  
Doping Profile ◽  
Quantum Model ◽  
Compatibility Conditions ◽  
Thermal Equilibrium State ◽  
Quantum Fluid ◽  
Charge Model ◽  
Differential Algebraic System ◽  
Space Charge Model

The thermal equilibrium state of a bipolar, isothermal quantum fluid confined to a bounded domain Ω⊂ℝd, d = 1, 2 or d = 3 is the minimizer of the total energy [Escr ]ελ; [Escr ]ελ involves the squares of the scaled Planck's constant ε and the scaled minimal Debye length λ. In applications one frequently has λ2[Lt ]1. In these cases the zero-space-charge approximation is rigorously justified. As λ → 0, the particle densities converge to the minimizer of a limiting quantum zero-space-charge functional exactly in those cases where the doping profile satisfies some compatibility conditions. Under natural additional assumptions on the internal energies one gets an differential-algebraic system for the limiting (λ = 0) particle densities, namely the quantum zero-space-charge model. The analysis of the subsequent limit ε → 0 exhibits the importance of quantum gaps. The semiclassical zero-space-charge model is, for small ε, a reasonable approximation of the quantum model if and only if the quantum gap vanishes. The simultaneous limit ε = λ → 0 is analyzed.

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