Colloidal quantum dots (CQDs) have large surface-to-volume ratios; thus, surface control is critical, especially when CQDs are utilized in optoelectronic devices. Layer-by-layer solid-state ligand exchange is a facile and applicable process for the formation of conductive CQD solids through various ligands; however, achieving complete ligand exchange on the CQD surface without dangling bonds is challenging. Herein, we demonstrate that CQDs can be further passivated through two-step annealing; air annealing forms sulfonate bonding at (111) Pb-rich surfaces, and subsequent N2 annealing removes insulating oxygen layers from the (100) surfaces of CQDs. By subsequently conducting annealing treatment in two different environments, traps on the surface of CQDs could be significantly reduced. We achieved a 40.8% enhancement of the power conversion efficiency by optimizing each two-step annealing process.
|Number of pages||7|
|Journal||ACS Applied Materials and Interfaces|
|Publication status||Published - 2020 Dec 30|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (nos. 2019R1A2C3008035, NRF-2020R1A4A1018516, and 2020M3H4A1A02084905).
© 2020 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)