Electron drift and diffusion via triple charged point defects in semiconductor crystals and diodes
Creators: name: Kavaleu, Aliaksandr Iharavich
Publisher: name: Zenodo
Year: 2018
Subjects: double and triple charged doping impurity atoms
triple charged t-defects of crystalline structure
hopping electrical conductivity
screening length
hopping diffusion length for electrons
p–n-diode with t-defects
current-voltage and capacitance-voltage characteristics

description: Kavaleu, A.I. Electron drift and diffusion via triple charged point defects in semiconductor crystals and diodes: extended abstract of PhD thesis ... phys. math. sci.: 01.04.10 / A.I. Kavaleu; Belarusian State University. – Minsk, 2018. – 22 p. (in Russian). <strong>Summary</strong> <strong>Keywords:</strong> double and triple charged doping impurity atoms, triple charged <em>t</em>-defects of crystalline structure, hopping electrical conductivity, screening length, hopping diffusion length for electrons, <em>p</em>–<em>n</em>-diode with <em>t</em>-defects, current-voltage and capacitance-voltage characteristics. <strong>The goal of this work: </strong>analytical and numerical study of ionization equilibrium, screening of external electric field, dc electrical conductivity and capacitance of semi­­conductor materials and <em>p</em>–<em>n</em>-diodes under the conditions of band-like and hopping migration of electrons and holes. <strong>Methods of the study:</strong> statistical physics of point defects, electrons and holes, analytical (in the linear approximation) and numerical solution of nonlinear differential equations by the finite difference method. <strong>The new results were obtained:</strong> 1) In a quasi-classical approximation for boron doped <em>p</em>-type diamond crystals, the temperature was specified, for which the conductivity of the <em>v</em>-band holes is equal to the hopping conductivity of holes via the acceptors (boron atoms) in the charge states (0) and (−1). 2) Dependence of the thermal activation energy of hopping electrical conductivity via boron atoms in diamond with respect to their concentration was calculated. 3) Calculation of the concentration-induced narrowing of the energy gap between the <em>D</em><sup>–</sup>(<em>A</em><sup>+</sup>)- and <em>D</em><sup>0</sup>(<em>A</em><sup>0</sup>)-bands of triple charged (−1, 0, +1) impurity atoms (<em>D</em> is for donors, <em>A</em> is for acceptors) was performed for <em>n</em>- and <em>p</em>-type semiconductors on the insulator side of the insulator–metal phase transition (Mott transition). 4) In the drift-diffusion approximation, the analytical expressions were found for the screening length of the stationary electric field and for the diffusion length of electrons hopping via <em>t</em>-defects in the charge states (−1), (0) and (+1). 5) A model for <em>p</em>–<em>n</em>-diode with electron transfer via <em>t</em>-defects was built; the model predicts an asymmetry of stationary hopping current depending on the polarity of the applied voltage. 6) A model of silicon based <em>p</em>–<em>n</em>-diode containing δ-layer of <em>t</em>‑defects in the region of plain <em>p</em>–<em>n</em>-junction was proposed. It was shown that due to the difference in the rate of generation and recombination for electrons and holes in δ-layer the diode has a region of forward current stabilization. <strong>Recommendations for the use and application area. </strong>The model of <em>p</em>–<em>n</em>-diode with uniformly distributed <em>t</em>-defects can be used for the elaboration of radiation-hardened hopping current rectifiers and the model with δ-layer of <em>t</em>-defects in the<br> <em>p</em>–<em>n</em>-junction can be used for producing stabilizers of the forward current.