Self-assembling of 1C4Sn and 4C10Sn clusters in Ge:(C, Sn)

Abstract

Carbon and Sn co-doping transforms Ge into Ge-rich CxSnyGe1−x−y alloy. Self-assembling of 1C4Sn and 4C10Sn clusters decreases the strain energy. These cluster formation processes are competing. The self-assembling conditions of 1C4Sn and 4C10Sn clusters are represented from 0 °C to 800 °C and at 5 × 10−5 ≤ x ≤ 0.015 and 1 × 10−4 ≤ y ≤ 0.015. The conditions demonstrate that only 1C4Sn clusters form if carbon is a minority impurity. Both types of clusters with the preferential formation of 4C10Sn clusters over 1C4Sn occur if the impurity concentrations are nearly equal or if Sn is a minority impurity.