Tailoring p-Type Behavior in ZnO Quantum Dots through Enhanced Sol–Gel Synthesis: Mechanistic Insights into Zinc Vacancies

• DOI: 10.1021/acs.jpclett.3c03519
• Publication Date: 2024-02-07T19:59:30Z
• Authors: Abdullah Kahraman; Etienne Socie; Maryam Nazari; Dimitrios Kazazis; Merve Buldu-Akturk; Victoria Kabanova; Elisa Biasin; Grigory Smolentsev; Daniel Grolimund; Emre Erdem; Jacques E. Moser; Andrea Cannizzo; Camila Bacellar; Christopher Milne
• Keywords: Colloidal zinc oxide; p-doping; Carrier dynamics; 000 Computer science, knowledge & systems; 620 Engineering; info:eu-repo/classification/ddc/530; 530; Ultrafast spectroscopy; Slow carrier recombination

Published by ACS, Washington, DC<br/>The journal of physical chemistry letters 15(6), 1755 - 1764 (2024). doi:10.1021/acs.jpclett.3c03519<br/>The synthesis and control of properties of p-type ZnO iscrucial for a variety of optoelectronic and spintronic applications;however, it remains challenging due to the control of intrinsic midgap(defect) states. In this study, we demonstrate a synthetic route to yieldcolloidal ZnO quantum dots (QD) via an enhanced sol−gel processthat effectively eliminates the residual intermediate reaction molecules,which would otherwise weaken the excitonic emission. This processsupports the creation of ZnO with p-type properties or compensationof inherited n-type defects, primarily due to zinc vacancies underoxygen-rich conditions. The in-depth analysis of carrier recombinationin the midgap across several time scales reveals microsecond carrierlifetimes at room temperature which are expected to occur via zinc vacancy defects, supporting the promoted p-type character of thesynthesized ZnO QDs.<br/>