Synthesis of III-V Semiconductor Particles from Organometallic Precursors

Reaction of the organometallic precursor molecules {[(CH3)3SiCH2]2In-P[Si(CH3)3]2}2 and {[(CH3)3SiCH2]2In-As[Si(CH3)3]2}2 with methanol yielded substantially pure precipitates of the III-V semiconductors InP and InAs. Addition of phenylphosphine or phenylarsine to the reaction mixtures effected “capping” of the growing semiconductor clusters, producing stable and soluble nanoclusters with organic surface groups, e.g. [(CH3)3SiCH2In] x[InP]y[PPh]z. Blue shifted absorption onsets in the optical spectra led to estimated cluster diameters of 55 A (InP) and 64 A (InAs). The nanoclusters as prepared were amorphous; however, they crystallized upon heating. Differential scanning calorimetry and X-ray diffraction have been used to characterize the crystallization process. Typical crystallization temperatures were close to 300°C and the associated activation energies ranged from 170 to 240 kJ/mol.