Facile synthesis of colloidal InAs nanocrystals using triphenylarsine as an arsenic source

• Colloidal InAs nanocrystals were synthesized by heating an organometallic solution.
• The solution contained stable triphenylarsine as the arsenic source.
• The average size of InAs nanocrystals obtained was varied from 12 nm to 20 nm.
• Widening of the optical gap due to quantum size effect was clearly observed.

Colloidal InAs nanocrystals (NCs) were synthesized by heating an organometallic solution, containing triphenylarsine as the arsenic source. Because the triphenylarsine is quite stable in ambient conditions at room temperature, the reaction is easy to handle compared with conventional synthesis using tris(trimethylsilyl)arsine. The average size of InAs NCs obtained was varied in the range from 12 nm to 20 nm according to the reaction time, and their optical gap was larger than that of the bulk InAs because of quantum size effect. The reaction mechanism of InAs NCs formation was discussed based on the infrared absorption spectra of reaction solutions, and formation of a reaction intermediate was suggested during the long induction period, ≈80 min, of InAs NCs formation.