CsPbI3 nanocrystals with narrow size distributions were readied to study the size-dependent properties. The nanocrystals adopt the perovskite (over the nonperovskite orthorhombic) structure with improved stability over thin-film materials. Among the perovskite phases (cubic α, tetragonal β, and orthorhombic γ), the samples are characterized by the γ phase, rather than α, but may have a size-dependent average tilting between adjacent octahedra. Size-dependent lattice constants systematically vary 3% across the size range, with unit cell volume increasing linearly with the inverse of size to 2.1% for the smallest size. We estimate the surface energy to be from -3.0 to -5.1 eV nm-2 for ligated CsPbI3 nanocrystals. Moreover, the size-dependent bandgap is best described using a nonparabolic intermediate confinement model. We experimentally determine the bulk bandgap, effective mass, and exciton binding energy, concluding with variations from the bulk a-phase values. This provides a robust route to understanding ..gamma..-phase properties of CsPbI3.
Zhao, Qian, et al. "Size-Dependent Lattice Structure and Confinement Properties in CsPbI<sub>3</sub> Perovskite Nanocrystals: Negative Surface Energy for Stabilization." ACS Energy Letters, vol. 5, no. 1, Dec. 2019. https://doi.org/10.1021/acsenergylett.9b02395
Zhao, Qian, Hazarika, Abhijit, Schelhas, Laura T., Liu, Jun, Gaulding, E. Ashley, Li, Guoran, Zhang, Minghui, Toney, Michael F., Sercel, Peter C., & Luther, Joseph M. (2019). Size-Dependent Lattice Structure and Confinement Properties in CsPbI<sub>3</sub> Perovskite Nanocrystals: Negative Surface Energy for Stabilization. ACS Energy Letters, 5(1). https://doi.org/10.1021/acsenergylett.9b02395
Zhao, Qian, Hazarika, Abhijit, Schelhas, Laura T., et al., "Size-Dependent Lattice Structure and Confinement Properties in CsPbI<sub>3</sub> Perovskite Nanocrystals: Negative Surface Energy for Stabilization," ACS Energy Letters 5, no. 1 (2019), https://doi.org/10.1021/acsenergylett.9b02395
@article{osti_1595568,
author = {Zhao, Qian and Hazarika, Abhijit and Schelhas, Laura T. and Liu, Jun and Gaulding, E. Ashley and Li, Guoran and Zhang, Minghui and Toney, Michael F. and Sercel, Peter C. and Luther, Joseph M.},
title = {Size-Dependent Lattice Structure and Confinement Properties in CsPbI<sub>3</sub> Perovskite Nanocrystals: Negative Surface Energy for Stabilization},
annote = {CsPbI3 nanocrystals with narrow size distributions were readied to study the size-dependent properties. The nanocrystals adopt the perovskite (over the nonperovskite orthorhombic) structure with improved stability over thin-film materials. Among the perovskite phases (cubic α, tetragonal β, and orthorhombic γ), the samples are characterized by the γ phase, rather than α, but may have a size-dependent average tilting between adjacent octahedra. Size-dependent lattice constants systematically vary 3% across the size range, with unit cell volume increasing linearly with the inverse of size to 2.1% for the smallest size. We estimate the surface energy to be from -3.0 to -5.1 eV nm-2 for ligated CsPbI3 nanocrystals. Moreover, the size-dependent bandgap is best described using a nonparabolic intermediate confinement model. We experimentally determine the bulk bandgap, effective mass, and exciton binding energy, concluding with variations from the bulk a-phase values. This provides a robust route to understanding ..gamma..-phase properties of CsPbI3.},
doi = {10.1021/acsenergylett.9b02395},
url = {https://www.osti.gov/biblio/1595568},
journal = {ACS Energy Letters},
issn = {ISSN 2380-8195},
number = {1},
volume = {5},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2019},
month = {12}}
Energy Frontier Research Centers (EFRC) (United States). Center for Hybrid Organic-Inorganic Semiconductors for Energy (CHOISE); National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1595568
Alternate ID(s):
OSTI ID: 1634005
Report Number(s):
NREL/JA--5900-74571
Journal Information:
ACS Energy Letters, Journal Name: ACS Energy Letters Journal Issue: 1 Vol. 5; ISSN 2380-8195