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Title: Correlation between Photoluminescence and Carrier Transport and a Simple In Situ Passivation Method for High-Bandgap Hybrid Perovskites

Abstract

High-bandgap mixed-halide hybrid perovskites have higher open-circuit voltage deficits and lower carrier diffusion lengths than their lower-bandgap counterparts. We have developed a ligand-assisted crystallization (LAC) technique that introduces additives in situ during the solvent wash and developed a new method to dynamically measure the absolute intensity steady-state photoluminescence and the mean carrier diffusion length simultaneously. The measurements reveal four distinct regimes of material changes and show that photoluminescence brightening often coincides with losses in carrier transport, such as in degradation or phase segregation. Further, the measurements enabled optimization of LAC on the 1.75 eV bandgap FA 0.83Cs 0.17Pb(I 0.66Br 0.34) 3, resulting in an enhancement of the photoluminescence quantum yield (PLQY) of over an order of magnitude, an increase of 80 meV in the quasi-Fermi level splitting (to 1.29 eV), an increase in diffusion length by a factor of 3.5 (to over 1 μm), and enhanced open-circuit voltage and short-circuit current from photovoltaics fabricated from the LAC-treated films.

Authors:
ORCiD logo [1];  [1];  [1];  [1]
  1. Univ. of Washington, Seattle, WA (United States). Molecular Engineering and Sciences Inst. Dept. of Chemical Engineering. Clean Energy Inst.
Publication Date:
Research Org.:
Univ. of Washington, Seattle, WA (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S); Washington Research Foundation (United States); State of Washington (United States)
OSTI Identifier:
1368596
Grant/Contract Number:
EE0006710
Resource Type:
Journal Article: Published Article
Journal Name:
Journal of Physical Chemistry Letters
Additional Journal Information:
Journal Volume: 8; Journal Issue: 14; Journal ID: ISSN 1948-7185
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Stoddard, Ryan J., Eickemeyer, Felix T., Katahara, John K., and Hillhouse, Hugh W.. Correlation between Photoluminescence and Carrier Transport and a Simple In Situ Passivation Method for High-Bandgap Hybrid Perovskites. United States: N. p., 2017. Web. doi:10.1021/acs.jpclett.7b01185.
Stoddard, Ryan J., Eickemeyer, Felix T., Katahara, John K., & Hillhouse, Hugh W.. Correlation between Photoluminescence and Carrier Transport and a Simple In Situ Passivation Method for High-Bandgap Hybrid Perovskites. United States. doi:10.1021/acs.jpclett.7b01185.
Stoddard, Ryan J., Eickemeyer, Felix T., Katahara, John K., and Hillhouse, Hugh W.. 2017. "Correlation between Photoluminescence and Carrier Transport and a Simple In Situ Passivation Method for High-Bandgap Hybrid Perovskites". United States. doi:10.1021/acs.jpclett.7b01185.
@article{osti_1368596,
title = {Correlation between Photoluminescence and Carrier Transport and a Simple In Situ Passivation Method for High-Bandgap Hybrid Perovskites},
author = {Stoddard, Ryan J. and Eickemeyer, Felix T. and Katahara, John K. and Hillhouse, Hugh W.},
abstractNote = {High-bandgap mixed-halide hybrid perovskites have higher open-circuit voltage deficits and lower carrier diffusion lengths than their lower-bandgap counterparts. We have developed a ligand-assisted crystallization (LAC) technique that introduces additives in situ during the solvent wash and developed a new method to dynamically measure the absolute intensity steady-state photoluminescence and the mean carrier diffusion length simultaneously. The measurements reveal four distinct regimes of material changes and show that photoluminescence brightening often coincides with losses in carrier transport, such as in degradation or phase segregation. Further, the measurements enabled optimization of LAC on the 1.75 eV bandgap FA0.83Cs0.17Pb(I0.66Br0.34)3, resulting in an enhancement of the photoluminescence quantum yield (PLQY) of over an order of magnitude, an increase of 80 meV in the quasi-Fermi level splitting (to 1.29 eV), an increase in diffusion length by a factor of 3.5 (to over 1 μm), and enhanced open-circuit voltage and short-circuit current from photovoltaics fabricated from the LAC-treated films.},
doi = {10.1021/acs.jpclett.7b01185},
journal = {Journal of Physical Chemistry Letters},
number = 14,
volume = 8,
place = {United States},
year = 2017,
month = 6
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1021/acs.jpclett.7b01185

Citation Metrics:
Cited by: 3works
Citation information provided by
Web of Science

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  • High-bandgap mixed-halide hybrid perovskites have higher open-circuit voltage deficits and lower carrier diffusion lengths than their lower-bandgap counterparts. We have developed a ligand-assisted crystallization (LAC) technique that introduces additives in situ during the solvent wash and developed a new method to dynamically measure the absolute intensity steady-state photoluminescence and the mean carrier diffusion length simultaneously. The measurements reveal four distinct regimes of material changes and show that photoluminescence brightening often coincides with losses in carrier transport, such as in degradation or phase segregation. Further, the measurements enabled optimization of LAC on the 1.75 eV bandgap FA 0.83Cs 0.17Pb(I 0.66Br 0.34)more » 3, resulting in an enhancement of the photoluminescence quantum yield (PLQY) of over an order of magnitude, an increase of 80 meV in the quasi-Fermi level splitting (to 1.29 eV), an increase in diffusion length by a factor of 3.5 (to over 1 μm), and enhanced open-circuit voltage and short-circuit current from photovoltaics fabricated from the LAC-treated films.« less
  • The polycrystalline feature of solutionprocessed perovskite film and its ionic nature inevitably incur substantial crystallographic defects, especially at the film surface and the grain boundaries (GBs). Here, a simple defect passivation method was exploited by post-treating CH 3NH 3PbI 3 (MAPbI 3) film with a rationally selected diammonium iodide. The molecular structure of the used diammonium iodide was discovered to play a critical role in affecting the phase purity of treated MAPbI 3. Both NH 3I(CH 2) 4NH 3I and NH 3I(CH 2) 2O(CH 2) 2NH 3I (EDBE) induce three-dimensional (3D) to two-dimensional (2D) perovskite phase transformation during the treatmentmore » while only NH 3I(CH 2) 8NH 3I (C 8) successfully passivates perovskite surface and GBs without forming 2D perovskite because of the elevated activation energy arising from its unique anti-gauche isomerization. In conclusion, defect passivation of MAPbI 3 was clearly confirmed by scanning Kelvin probe microscopy (SKPM) and time-resolved photoluminescence (TRPL) studies, which results in the reduced recombination loss in derived devices. Consequently, the perovskite solar cell with C 8 passivation showed a much improved power conversion efficiency (PCE) of 17.60% compared to the control device PCE of 14.64%.« less
  • The carrier mobility of pentacene thin-film transistor is studied by passivating the surface of its SiO{sub 2} gate dielectric in NH{sub 3} at different temperatures, namely, 900, 1000, 1100, and 1150 deg. C. Measurements demonstrate that the higher the annealing temperature, the higher the carrier mobility of the OTFT is. The device annealed at 1150 deg. C has a field-effect mobility of 0.74 cm{sup 2}/V s, which is 35% higher than that of the device annealed at 900 deg. C. Energy-dispersive x-ray analysis, scanning-electron microscopy, and atomic-force microscopy show that the higher carrier mobility should be due to more nitrogenmore » incorporated at the gate-dielectric surface which results in more passivated dielectric surface and larger pentacene grains for carrier transport.« less
  • The Shockley-Queisser limit for solar cell efficiency can be overcome if hot carriers can be harvested before they thermalize. Recently, carrier cooling time up to 100 picoseconds was observed in hybrid perovskites, but it is unclear whether these long-lived hot carriers can migrate long distance for efficient collection. Here, we report direct visualization of hot-carrier migration in methylammonium lead iodide (CH 3NH 3PbI 3) thin films by ultrafast transient absorption microscopy, demonstrating three distinct transport regimes. Quasiballistic transport was observed to correlate with excess kinetic energy, resulting in up to 230 nanometers transport distance that could overcome grain boundaries. Themore » nonequilibrium transport persisted over tens of picoseconds and ~600 nanometers before reaching the diffusive transport limit. Lastly, these results suggest potential applications of hot-carrier devices based on hybrid perovskites.« less
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