Colloidal Chemistry in Molten Inorganic Salts—Direct Synthesis of III-V Quantum Dots via Dehalosilylation of (Me₃Si)₃Pn (Pn=P, As) with Group III-Halides

Gallium pnictides, such as GaAs and GaP, are among the most widely used materials for electronic, opto-electronic, and photonic applications. However, the solution colloidal synthesis of gallium pnictides is underdeveloped compared to many other colloidal semiconductors, including indium pnictides, II-VI, IV-VI, and lead halide perovskites. In this work, we demonstrate that Wells dehalosilylation reaction can be carried out in molten inorganic salt solvents to synthesize colloidal GaAs, GaP and GaP_1-xAs_x nanocrystals. We demonstrate that discrete colloidal nanocrystals with control over size and composition can be nucleated and grown in a molten salt. We provide evidence that reaction temperatures above 400 deg C are crucial for eliminating structural defects in GaAs nanocrystals. We also show that GaP can be solution processed into high refractive index coatings and patterned by direct lithography^1–5 with micron resolution. Finally, we demonstrate that the dehalosilylation reactions in molten salts can be generalized to synthesize indium pnictide (InP, InAs) and ternary (In_1-xGa_xAs, In_1-xGa_xP) quantum dots.