My research interests encompass programmable colloidal nanoscale materials for single-photon sources, imaging, energy applications, and biological applications. In the first direction, my group will explore the chemistry at the interface of “traditional” colloidal nanomaterials and the emerging field of two-dimensional materials to produce programmable functional heterostructures. In the second direction, we will synthesize stable, highly luminescent heterostructures of near-IR semiconductors as potential quantum emitters. In the third direction, my group will develop electrochemical methods to monitor and quantify hot syntheses and post-synthetic modifications of nanomaterials in situ.

1. Colloidal chemistry of 2D materials

Colloidal semiconductor quantum dots (QDs) are tunable quantum-confined materials used in TV displays and biological imaging and making their way into QLEDs, infrared photonic devices, and on-demand single-photon emitters. On the other hand, layered 2D materials (e.g., MoS₂, WSe₂) have gained much interest in the past two decades and have shown a great potential for applications in catalysts, batteries, supercapacitors, solar cells, and other optoelectronic devices. I would like to to bring synthetic and characterization tools from “traditional” colloidal semiconductor nanocrystals (NCs) into the emerging field of 2D layered materials. This direction of my research program will focus on (1) preparation, (2) functionalization, and (3) integration of colloidal 2D materials. Starting with transition metal dichalcogenides (TMDs), my group will develop chemical exfoliation methods that will produce colloidal solutions of layered materials of desired thickness, lateral size, and dispersant. Next, we will work out functionalization of colloidal 2D materials to integrate them into complex functional assemblies.

2. Pnictide-based NIR quantum dots for on-demand single-photon emitters

Near-IR materials have gained a big interest as potential on-demand emitters for quantum communication. Therefore, in the second direction, I would like to advance the field of luminescent colloidal III–V and II–V semiconductors (e.g., InAs, Cd₃P₂). We will combine the world best practices in colloidal III–V QDs with the rich experience in compositional grading to engineer highly luminescent near-IR on-demand emitters.

3. Probing the hot synthesis of nanocrystals in situ

Over the past three decades, the synthesis of colloidal nanocrystals (NCs) has evolved to afford programmable materials with desired shapes and complex compositions to address numerous technological demands. Because understanding molecular mechanisms of the NC synthesis enables us to produce structures of various complexities, probing hot syntheses of QDs in situ has earned the attention of chemists. In this third direction, my group will employ electrochemical tools to monitor, quantify, and manipulate NC syntheses. My group will extend electrochemistry to elevated temperatures and nonpolar solvents to understand the evolution of clusters and NCs during the synthesis.