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arXiv · 1704.02200

On the impact ionization rate in direct gap semiconductors

A. N. Afanasiev·A. A. Greshnov·G . G. Zegrya
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Abstract

We present quantum-mechanical theory of impact ionization in semiconductors with the direct band gap in \$\Gamma\$-point. It is shown that energy dependence of the impact ionization rate \$\mathcal{W}(E)\$ near a threshold \$E_{th}\$ is given by superposition of the two terms, one of which is strongly anisotropic and quadratic in \$E-E_{th}\$, while another one is isotropic and cubic in \$E-E_{th}\$. Explicit form of the coefficients in such representation is derived in the framework of the 14-band \${\bf k\cdot p}\$ model, and we claim the room temperature domination of the cubic contribution for most of the direct-gap materials with \$E_g\$ up to 1.5 eV.

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A. N. Afanasiev, A. A. Greshnov, G . G. Zegrya. 2017-04-07. On the impact ionization rate in direct gap semiconductors. https://doi.org/10.1134/s0021364017090065

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