Donor Levels in n‐InSb and Their Ionization in Electric Field

The temperature dependences of the Hall coefficient R H , the conductivity σ, and the electron mobility μ in n‐type InSb samples with different degree of compensation have been investigated. Deep donor levels have been found at E c −1.8 × 10 −2 eV and E c −6.7 × 10 −2 eV. The parameters of these levels were estimated in terms of the many‐level model. The voltage‐current characteristics and the dependences R H = f ( E ) and R H σ = f ( E ) have been studied in detail at T =4.2 °K. It is shown that at E ≈ (2 to 8) × 10 −2 V/cm a partial ionization of the shallow donor level E c −6 × 10 −4 eV can occur (tunnel transition), whereas at E > 10 −1 V/cm an impact ionization of the donor level E c − 1.8 × 10 −2 eV is produced by electrons heated by the electric field.