Self-Organized Nanostructure Formation of III-V and IV Semiconductors with Bismuth

Abstract

III-V and group IV semiconductor nanostructures such as quantum dots (QDs) are expected for various applications. In this study, effects of Bi supply during the deposition process on the self-organized nanostructure formation were examined for III-V and group IV semiconductor materials. It was found that Bi was successfully acted as a surfactant to form In(Ga)As QDs by MOVPE growth. By this method, QDs with superior optical quality were obtained. The unique features, such as ripening during the In(Ga)As QD formation and the phenomenon during the covering layer growth are discussed. As for the new approach on Ge-based nanostructure formation, high-density dot-like nanostructures were obtained by the low-temperature deposition sequence of Bi and Ge on SiO2 substrates. As the formation mechanism has not been revealed yet, we suggest hypotheses for that of the Bi and Ge system.