Hydrogen Treatment as a Detergent of Electronic Trap States in Lead Chalcogenide Nanoparticles
| Autor: | Nicholas P. Brawand, Giulia Galli, Márton Vörös |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Passivation Hydrogen Chalcogenide General Chemical Engineering Doping Inorganic chemistry Nanoparticle chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences chemistry.chemical_compound chemistry Impurity Materials Chemistry Density functional theory 0210 nano-technology Stoichiometry |
| Zdroj: | Chemistry of Materials. 29:2485-2493 |
| ISSN: | 1520-5002 0897-4756 |
| DOI: | 10.1021/acs.chemmater.6b04126 |
| Popis: | Lead chalcogenide (PbX) nanoparticles are promising materials for solar energy conversion. However, the presence of trap states in their electronic gap limits their usability, and developing a universal strategy to remove trap states is a persistent challenge. Using calculations based on density functional theory, we show that hydrogen acts as an amphoteric impurity on PbX nanoparticle surfaces; hydrogen atoms may passivate defects arising from ligand imbalance or off-stoichiometric surface terminations irrespective of whether they originate from cation or anion excess. In addition, we show, using constrained density functional theory calculations, that hydrogen treatment of defective nanoparticles is also beneficial for charge transport in films. We also find that hydrogen adsorption on stoichiometric nanoparticles leads to electronic doping, preferentially n-type. Our findings suggest that postsynthesis hydrogen treatment of lead chalcogenide nanoparticle films is a viable approach to reduce electronic ... |
| Databáze: | OpenAIRE |
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