Reassessment of the intrinsic carrier density in crystalline silicon in view of band-gap narrowing

The commonly used value of the intrinsic carrier density of crystalline silicon at 300 K is n(i) = 1.00 x 10(10) 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 10116 cm-3). We reinterpret their measurements by numerical simulations with a random-phase approximation model for band-gap narrowing, thereby obtaining n(i) = 9.65. x 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. (C) 2003 American Institute of Physics. [DOI: 10.1063/1.1529297].