Modulating Charge Carrier Dynamics and Transfer via Surface Modifications in Organometallic Halide Perovskite Quantum Dots
| Autor: | William Delmas, Evan T. Vickers, Jin Z. Zhang, Sayantani Ghosh, Albert DiBenedetto, Isaak N. Hernandez, Calista Lum |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Exciton Halide 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Delocalized electron chemistry.chemical_compound chemistry Chemical physics Quantum dot General Materials Science Charge carrier Physical and Theoretical Chemistry 0210 nano-technology Benzoic acid Doppler broadening Perovskite (structure) |
| Zdroj: | The journal of physical chemistry letters. 11(18) |
| ISSN: | 1948-7185 |
| Popis: | We investigate the effect of functionalization by acid/amine combinations of four aromatic capping ligands on the optoelectronic properties of CH3NH3PbBr3 perovskite quantum dots (PQDs). These include benzoic acid (BA), phenylacetic acid (PAA), benzylamine, and isopropyl benzylamine. We observe that charge transfer efficiency in PQD films comprising BA-ligated samples varies between 12% and 95% as the dot density is tuned from 102 to 105 dots/μm2 but is consistently ∼92% over that entire range for PAA-ligated PQDs. As temperature T decreases, initially, recombination is dominated by bound or trapped excitons, but below 80 K, spectral broadening, accompanied by free excitonic behavior, is observed. Our results indicate enhanced charge delocalization at lower values of T, which reduces the level of exciton confinement and recombination decay rates and underlines the importance of investigating PQD-ligand interactions at a fundamental level given the significant effect minute changes in ligand structures have on the optoelectronic properties of quantum dots. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|