The commonly used value of the intrinsic carrier density of crystalline silicon at 300 K is ni=1.00×1010 cm−3. It was experimentally determined by Sproul and Green, J. Appl. Phys. 70, 846 (1991), using specially designed solar cells. In this article, we demonstrate that the Sproul and Green experiment was influenced by band-gap narrowing, even though the dopant density of their samples was low (1014 to 1016 cm−3). We reinterpret their measurements by numerical simulations with a random-phase approximation model for band-gap narrowing, thereby obtaining ni=9.65×109 cm−3 at 300 K. This value is consistent with results obtained by Misiakos and Tsamakis, J. Appl. Phys. 74, 3293 (1993), using capacitance measurements. In this way, long-prevailing inconsistencies between independent measurement techniques for the determination of ni are resolved.

The radiative recombination coefficient B in crystalline bulk silicon is enhanced by the Coulomb attraction between electrons and holes. This effect is weakened at high carrier densities due to screening. We measure the resulting dependence of B on the free-carrier density (i) by reinterpreting published data and (ii) with photoluminescence and photovoltaic measurements. We calculate the Coulomb enhancement by determining the electron-hole pair correlation function at zero interparticle distance, assuming a Debye interaction potential. Both bound and scattering state contributions are fully taken into account. Due to screening, B decreases with increasing free-carrier density.

The radiative recombination coefficient B in crystalline bulk silicon is enhanced by the Coulomb attraction between electrons and holes. This effect -and hence B -is reduced at high carrier densities due to screening. We measure and numerically calculate B as a function of injection density, and with the gained model we simulate an experiment in order to extract the Coulomb-enhancement of Auger recombination.

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