Synthesis and conversion of InAs_xP_1-x alloy nanoclusters

III-V semiconductor alloys offer a powerful platform for optical gap engineering, yet achieving tunable compositional control in colloidal nanocrystals remains a challenge. Here, we report a nanocluster-mediated strategy for the synthesis of compositionally tunable InAs_xP_1-x alloy nanocrystals. InAs_xP_1-x nanoclusters with varied As : P anion ratios were synthesized using a bottom-up method and isolated to establish alloy composition before growth to nanocrystals via thermolysis. By varying cluster composition, a tunable optical gap range of 3.1 to 2.7 eV can be achieved. These nanoclusters were then used as single-source precursors in a second extended growth step to further tune the size and resulting optical gap of the alloy nanocrystals. This two-step approach demonstrates continuous optical gap modulation from 3.1 to 1.9 eV through coupling of both initial nanocluster composition and quantum confinement of the resulting nanocrystals. To enhance the optical properties, InAs_xP_1-x cores were shelled with ZnSe, leading to an increase in photoluminescence intensity through surface passivation. This work demonstrates that nanocluster precursors serve as a platform for systematic alloy control in colloidal III-V semiconductors and provides a route to compositionally and size-tunable alloy nanocrystals.