Synthesis and Characterization of Tetrapod-Shaped InP/ZnSe/ZnS Core/Shell/Shell Quantum Dots

InP colloidal quantum dots(CQDs) have 1.35 eV of bulk bandgap that can cover the visible spectral region by controlling their size owing to the quantum confinement effect. In addition, InP CQDs are applied to the visible optoelectronic devices as an alternative for heavy metal (Cd-, Pb-) containing materials. Recently, single-crystalline InP tetrapod nanoparticles through the surface energy-driven growth have been reported.[1] Single-crystalline InP tetrapod QDs have only zinc blende structure, it is clearly different crystal structure from typically reported heterostructure nanotetrapods (e.g., tetrapod has a zinc blende core and four wurtzite arms).[2] Although novel optical and physical properties are expected in single-crystalline InP tetrapod QDs, some challenges, such as low photoluminescence (PL) and stability in ambient condition, limit the optoelectronic analyses. In this study, we especially focus on the shell passivation approach using ZnSe and ZnS on the tetrapod InP core with maintaining their shape to overcome these issues. Various reaction conditions are investigated for conformal shell growth on the core. Finally, the optical properties, structure, and shape of the tetrapod-shaped InP/ZnSe/ZnS core/shell/shell are analyzed through absorbance, PL, TEM, and XRD measurements.<br/>[1] S. Jeong et al. <i>Nat Commun</i>. <b>2021</b>, 12, 4454<br/>[2] A. P. Alivisatos et al. <i>Nano Lett</i>. <b>2007</b>, 7, 10