High Temperature Transport Property of B- and P-Doped GeSi Single Crystals Prepared by a Czochralski Method

Abstract

B-doped (p-type) and P-doped (n-type) Ge_0.07Si_0.93 single crystals were prepared by a Czochralski (CZ) method. The anisotropy of Seebeck coefficient (α), electrical conductivity (σ) and thermal conductivity (κ) among the [001], [110] and [111] directions was determined and the values were compared with those of polycrystalline materials. The Seebeck coefficient of B-doped specimen in the [111] direction (α₁₁₁) was the same as that in the [110] direction (α₁₁₀), and was greater than that in the [001] direction (α₀₀₁) measured at all temperature. The α₁₁₁, α₁₁₀ and α₁₀₀ of the P-doped specimens were in agreement above 600 K, but anisotropy of α values was observed below 500 K, (|α₀₀₁|>|α₁₁₁|>|α₁₁₀|). No anisotropy of σ and κ was observed in both B- and P-doped specimens. The thermal conductivity of B- and P-doped single crystal specimens were much greater than that of polycrystalline materials.