TY - JOUR
T1 - Influence of Halides on the Interactions of Ammonium Acids with Metal Halide Perovskites
AU - Li, Yanan
AU - Lohr, Patrick J.
AU - Segapeli, Allison
AU - Baltram, Juliana
AU - Werner, Dorian
AU - Allred, Alex
AU - Muralidharan, Krishna
AU - Printz, Adam D.
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation under grant no. 2237211. This work was further supported by laboratory startup funds from the University of Arizona. P.J.L. was supported by the financial and in-kind contributions of the University of Arizona University Fellows Program. The authors thank the following user facilities at the University of Arizona. All Park AFM images and data were collected in the W.M. Keck Center for Nano-Scale Imaging in the Department of Chemistry and Biochemistry at the University of Arizona, RRID:SCR_022884. This instrument purchase was partially supported by Arizona Technology and Research Initiative Fund (A.R.S.§15–1648). All X-ray and ultraviolet photoelectron spectra were collected at the Laboratory for Electron Spectroscopy and Surface Analysis (LESSA) in the Department of Chemistry and Biochemistry at the University of Arizona, RRID:SCR_022885, using a Kratos Axis 165 Ultra DLD Hybrid Ultrahigh Vacuum Photoelectron Spectrometer. The instrument was purchased with funding from the National Science Foundation and supported by the Center for Interface Science: Solar-Electric Materials (CIS:SEM), an Energy Frontier Research Center funded by the U.S. Department of Energy and Arizona Technology and Research Initiative Fund (A.R.S.§15-1648). The powder XRD measurements were performed at the XRD facility in the Department of Chemistry and Biochemistry of the University of Arizona, RRID:SCR_022886, on a Philips PANalytical X’Pert PRO MPD instrument. The authors acknowledge NASA grants #NNX12AL47G and #NNX15AJ22G and NSF grant #1531243 for funding of the instrumentation in the Kuiper Materials Imaging and Characterization Facility at the University of Arizona. UV–vis spectrometry was performed at the Micro/Nanofabrication Center at the University of Arizona. DFT calculations were performed upon High Performance Computing (HPC) resources supported by the University of Arizona TRIF, UITS, and Research, Innovation, and Impact (RII) and maintained by the University of Arizona Research Technologies Department.
Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/5/24
Y1 - 2023/5/24
N2 - Additive engineering is a common strategy to improve the performance and stability of metal halide perovskite through the modulation of crystallization kinetics and passivation of surface defects. However, much of this work has lacked a systematic approach necessary to understand how the functionality and molecular structure of the additives influence perovskite performance and stability. This paper describes the inclusion of low concentrations of 5-aminovaleric acid (5-AVA) and its ammonium acid derivatives, 5-ammoniumvaleric acid iodide (5-AVAI) and 5-ammoniumvaleric acid chloride (5-AVACl), into the precursor inks for methylammonium lead triiodide (MAPbI3) perovskite and highlights the important role of halides in affecting the interactions of additives with perovskite and film properties. The film quality, as determined by X-ray diffraction (XRD) and photoluminescence (PL) spectrophotometry, is shown to improve with the inclusion of all additives, but an increase in annealing time from 5 to 30 min is necessary. We observe an increase in grain size and a decrease in film roughness with the incorporation of 5-AVAI and 5-AVACl with scanning electron microscopy (SEM) and atomic force microscopy (AFM). Critically, X-ray photoelectron spectroscopy (XPS) measurements and density functional theory (DFT) calculations show that 5-AVAI and 5-AVACl preferentially interact with MAPbI3 surfaces via the ammonium functional group, while 5-AVA will interact with either amino or carboxylic acid functional groups. Charge localization analysis shows the surprising result that HCl dissociates from 5-AVACl in vacuum, resulting in the decomposition of the ammonium acid to 5-AVA. We show that device repeatability is improved with the inclusion of all additives and that 5-AVACl increases the power conversion efficiency of devices from 17.61 ± 1.07 to 18.07 ± 0.42%. Finally, we show stability improvements for unencapsulated devices exposed to 50% relative humidity, with devices incorporating 5-AVAI and 5-AVACl exhibiting the greatest improvements.
AB - Additive engineering is a common strategy to improve the performance and stability of metal halide perovskite through the modulation of crystallization kinetics and passivation of surface defects. However, much of this work has lacked a systematic approach necessary to understand how the functionality and molecular structure of the additives influence perovskite performance and stability. This paper describes the inclusion of low concentrations of 5-aminovaleric acid (5-AVA) and its ammonium acid derivatives, 5-ammoniumvaleric acid iodide (5-AVAI) and 5-ammoniumvaleric acid chloride (5-AVACl), into the precursor inks for methylammonium lead triiodide (MAPbI3) perovskite and highlights the important role of halides in affecting the interactions of additives with perovskite and film properties. The film quality, as determined by X-ray diffraction (XRD) and photoluminescence (PL) spectrophotometry, is shown to improve with the inclusion of all additives, but an increase in annealing time from 5 to 30 min is necessary. We observe an increase in grain size and a decrease in film roughness with the incorporation of 5-AVAI and 5-AVACl with scanning electron microscopy (SEM) and atomic force microscopy (AFM). Critically, X-ray photoelectron spectroscopy (XPS) measurements and density functional theory (DFT) calculations show that 5-AVAI and 5-AVACl preferentially interact with MAPbI3 surfaces via the ammonium functional group, while 5-AVA will interact with either amino or carboxylic acid functional groups. Charge localization analysis shows the surprising result that HCl dissociates from 5-AVACl in vacuum, resulting in the decomposition of the ammonium acid to 5-AVA. We show that device repeatability is improved with the inclusion of all additives and that 5-AVACl increases the power conversion efficiency of devices from 17.61 ± 1.07 to 18.07 ± 0.42%. Finally, we show stability improvements for unencapsulated devices exposed to 50% relative humidity, with devices incorporating 5-AVAI and 5-AVACl exhibiting the greatest improvements.
KW - ammonium halide salt additives
KW - first principles
KW - halide exchange
KW - hybrid organic-inorganic lead halide perovskites
KW - multifunctional additives
KW - perovskite solar cells
KW - surface passivation
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U2 - 10.1021/acsami.3c01432
DO - 10.1021/acsami.3c01432
M3 - Article
C2 - 37162743
AN - SCOPUS:85160006555
SN - 1944-8244
VL - 15
SP - 24387
EP - 24398
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 20
ER -