Photoionization cross sections of holes at zinc centers in silicon

摘要

The spectral dependences of the photoionization cross sections for holes at neutral and singly ionized zinc centers are measured using photocapacitance transient techniques in n + p junctions. Lucovsky's delta function potential model fits the results well. The photoionization cross section for holes at singly ionized zinc centers is much greater than the photoionization cross section for electrons at doubly ionized zinc centers. A large electric field dependence and a small temperature dependence are observed near the absorption edge of the photoionization cross section for holes at singly ionized zinc centers. The temperature dependence indicates a possible two‐step photothermal process has taken place when the center is photoionized.