Structural changes caused by quenching of InAs/GaAs(001) quantum dots

InAs/GaAs(001)量子ドットの急冷時に生じる構造変化

高橋 正光; 藤川 誠司

Takahashi, Masamitsu; Fujikawa, Seiji

Self-assembled InAs/GaAs(001) quantum dot structures before and after quenching were investigated by in situ X-ray diffraction to assess the influences of quenching. Before quenching, quantums dots were uniform in size so that the shape and internal lattice constant distribution of a quantum dot were quantitatively determined on the basis of three-dimensional X-ray intensity mapping. X-ray measurements after quenching revealed that the quantum dot size showed a bimodal distribution as a result of proliferation of dislocated islands during quenching. A formula to describe the X-ray diffraction from dislocated islands with a large size distribution is presented. The quenching rate has little influence on the structures of quenched quantum dots for the cooling rate investigated.