Manipulation of Precursor Coordination and Reactivity to Enable Phase-tunability in Colloidally Synthesized Transition Metal Dichalcogenide Nanocrystals

点击翻译按钮获取中文摘要

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program in the Division of Chemistry, Professor Alina Schimpf at University of California, San Diego is developing new strategies for the synthesis of transition metal dichalcogenides (TMDs). This class of materials has a wide array of potential applications including advanced electronics, chemical catalysis, and quantum information science. The properties of a TMD depend not only on their atomic composition, but also on the specific atomic arrangement (the crystal phase). To uncover their technological potential, the ability to generate phases of interest in pure form is critical. Unlike traditional solid-state syntheses, Professor Schimpf and her group use solution chemistry to directly synthesize TMDs of the same phase. The information garnered through targeted efforts on this type of TMDs is broadly applicable to and informs the synthesis of other TMDs and inorganic materials. Professor Schimpf is also using these studies as a platform to provide research experiences for community college students by partnering with San Diego Mesa College, an Hispanic Serving Institution. The educational outreach activity provides opportunities for students to work alongside PhD chemists and learn about advanced chemistry research. Transition metal dichalcogenides (TMDs) are poised to play an important role in emerging technologies, with potential uses in electronics, optoelectronics, catalysis and quantum spin information science. The various applications of these materials are derived from different crystal phases, giving rise to unique and diverse electronic and photophysical properties. Professor Schimpf’s research uses colloidal chemistry to access phase-tunable syntheses of group-VI TMDs with composition ME2 (M = Mo, W; E = S, Se) by exploiting the coordination chemistry and reactivity of the molecular precursors. This research explores the chemical principles that govern the ability to synthesize and maintain metastable phases. The primary objective is to develop a microscopic understanding of the chemistry that governs nanocrystal formation in order to rationally synthesize TMD nanocrystals with the desired properties. The insights gained from this research are being used to hone the design principles and iteratively add complexity to the structural design, enabling access to higher-quality and phase-pure inorganic materials. These studies may ultimately enable new strategies to access new or exotic phases of a wide range of TMDs. Professor Schimpf is also working with community college students from San Diego Mesa College, a local Hispanic Serving Institution, by engaging them in the research of designing and conducting syntheses of WS2 nanocrystals.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.