Effect of Annealing on The Behavior of Oxygen Dissolved in Germanium and Optical Properties of Single Crystals

Abstract

The annealing effect in the temperature range from 350 to 450 ∘C on the behavior of interstitial oxygen O𝑖 dissolved in germanium and on optical properties of single crystals has been investigated by Fourier transformed infrared spectrometry. It was found that oxygen band maximum of 843 cm−1 shifted toward the 856 cm−1 with oxygen concentration increasing after annealing at the oxygen partial pressure ranged from 1 to 103 Pa. The annealing at lower 𝑃𝑂 2 values led to the decrease of 843 cm−1 band intensity due to the formation of thermal donors (TD) on the basis of dissolved oxygen atoms O𝑖. It was established that TD formation and the decrease of unbound oxygen concentration affected optical properties of the crystals.