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Electronic Supplementary Material (ESI) for J. Mater. Chem. A

Electron-Beam Irradiation-Hard Metal-Halide Perovskite Nanocrystals

Wenna Liu1,2,, Jinju Zheng2,, Minghui Shang2, Zhi Fang1,2, Kuo-Chih. Chou1, Weiyou

Yang2,, Xinmei Hou1,, and Tom Wu3,

1 State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing

100083, P.R. China.

2 Institute of Materials, Ningbo University of Technology, Ningbo City, 315016, P.R. China.

3 School of Materials Science and Engineering, University of New South Wales (UNSW), Sydney,

NSW 2052, Australia

Equal Contribution Authors

Corresponding Author E-mails: weiyouyang@tsinghua.org.cn (W. Yang)

houxinmeiustb@ustb.edu.cn (X. Hou)

tom.wu@unsw.edu.au (T. Wu)

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2019

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Experimental Procedure

Materials. Cesium carbonate (Cs2CO3, 99.99%), lead (II) chloride (PbCl2, 99.99%), oleic acid

(OA, 90%), oleylamine (OAm, 80%), trioctylphosphene (TOP, 90%), manganese chloride (MnCl2,

99%), hydrochloric acid (HCl, 33.4%), octadecene (ODE, 90%), diethylene glycol butyl ether (DGBE,

98%) and hexane (97%, anhydrous grade) were purchased from Aldrich. All chemicals were used

directly without further purification.

Preparation of OAm-HCl (RNH3Cl): For the preparation of RNH3Cl precursor solution, 10 mL

of oleylamine (OAm) and 1 mL of HCl were loaded in a 25 mL 3-neck round bottomed flask. At 80°C,

the mixture was purged with N2 for 1 h. Then the solution was heated for 2 h at 120°C under N2,

followed by being stored under N2. For the next use, such solution was heated up to 80°C again.

Preparation of Cs-oleate: In a typical process for the preparation of Cs-oleate precursor solution,

0.8 g Cs2CO3, 2.4 mL OA and 30 mL ODE were loaded together into a 3-neck flask, followed by being

dried for 1 h at 120°C, and then heated up to 150°C for 30 min under N2, until the Cs2CO3 was

dissolved completely. Before the use, the as-prepared solution was preheated over 100°C to circumvent

the Cs-oleate precipitation out of ODE at room temperature.

Synthesis of CsPbCl3 NCs: In a typical procedure, 111 mg PbCl2, 13 mL ODE, 2 mL DGBE, 2

mL OA, 2 mL OAm, 2 mL TOP and 2 mL RNH3Cl were loaded in a 25 mL three-necked flask, and

heated up to 190°C in a microwave oven with an power of 400 W under Ar atmosphere. After that, 0.85

mL Cs-oleate was injected swiftly. The CsPbCl3 NCs were then allowed to grow for 5 s at the preset

temperature, followed by cooling down to room temperature in a water bath. Subsequently, the obtained

NCs were cleaning with hexane and acetone and re-dispersed in hexane for further use. For the growth

of Mn2+-doped CsPbCl3 NCs, 50 mg MnCl2 were added into the raw materials additionally, with

otherwise experimental conditions as mentioned above.

Characterization. The morphology, composition and phase compositions of as-prepared CsPbCl3

NCs were examined using transmission electron microscopy (TEM, JEM-2100F, JEOL, Japan),

inductively coupled plasma optical emission spectrometry (ICP-OES, Ultima 2, Horiba Jobin Yvon,

France) and X-ray diffraction (D8 Advance, Bruker, Germany). The UV-Vis measurements of the

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obtained NCs were taken on a UV-Vis scanning spectrophotometer (U-3900, Hitachi, Japan). The PL

and PL QY were recorded using a spectrometer (Fluoromax-4P, Horiba Jobin Yvon, France) equipped

with a quantum-yield accessory. To monitor the stability of the resultant CsPbCl3 NCs, the

microstructures bombarded by the electron beam emitted for the TEM electron guns were recorded with

various irradiation time.

Calculation Methods. To investigate the effect of Mn2+ dopants on the stability of CsPbCl3

perovskites, the electronic band structure, charge density difference and formation energy was

calculated based on density functional theory (DFT) employing the Perdew-Burke-Ernzerhof (PBE)

exchange and correlation functional,1 as implemented in Vienna Ab-initio Simulation Package (VASP).2

Electron-ion interaction was described by the projector-augemented wave (PAW) potentials with a

kinetic energy cutoff of 450 eV.3 Electrons taken to be valence are: 5s25p66s1 of Cs, 6s26p2 of Pb, 3d54s2

of Mn and 3s23p5 of Cl. The GGA+U method was applied with an effective U = 9 eV for the 3d

electrons of Mn.4 The structure relaxation is stopped when the force on each atom is below 0.05 eV/Å.

The systems of CsPb1-xMnxCl3 (x=0, 0.042, 0.063, 0.083) with various Mn2+ doping concentrations were

modeled by 2×3×4, 2×2×4 and 2×2×3 supercells, respectively, and the corresponding integration within

running over the Brillion zoon was sampled by 3×2×1, 3×3×1 and 3×3×2 k-point meshes centered at the

Г point, respectively.

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Fig. S1 (a) The UV-vis absorptions of the CsPbCl3 NCs before and after Mn2+ doping. (b) Excitation

spectrum of the Mn2+-doped CsPbCl3 NCs

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Fig. S2 Snapshots of a time series of TEM images of pure CsPbCl3 NCs under e-beam irradiation at an

acceleration voltage of 200 KeV. The scale bar is 10 nm.

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Fig. S3 TEM images of the pure CsPbCl3 NCs under low magnifications to show the structure damage

before (a) and after (b) e-beam irradiation for 6 min at an acceleration voltage of 200 KeV.

a b

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Fig. S4 Typical TEM image of Mn2+-doped CsPbCl3 NCs after e-beam irradiation for 6 min at an

acceleration voltage of 200 KeV.

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Fig. S5 Snapshots of a time series of TEM images of Mn2+-doped CsPbCl3 NCs taken at an acceleration

voltage of 200 KeV. The scale bar is 10 nm.

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Fig. S6 Typical TEM image of Mn2+-doped CsPbCl3 NCs with and without electron beam

bombardment for 30 min at an acceleration voltage of 200 KeV.

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Fig. S7 EDX analysis of the pure CsPbCl3 NCs after exposing to e-beam irradiation for 6 min. (a) TEM

image of the study area; (b) element content analyses from three randomly selected black dots in a. (c-

d) Typical elemental mappings recorded from the yellow box marked area in a.

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Fig. S8 (a1-a3) Typical TEM, HRTEM images and SAED pattern of pure CsPbCl3 NCs before e-beam irradiation,

respectively. (b1-b3) Typical TEM, HRTEM images and SAED pattern of pure CsPbCl3 NCs after e-beam irradiation

for 6 min, respectively. (c1-c3) Typical TEM, HRTEM images and SAED pattern of Mn2+-doped CsPbCl3 NCs before

e-beam irradiation, respectively. (d1-d3) Typical TEM, HRTEM images and SAED pattern of Mn2+-doped CsPbCl3

NCs after e-beam irradiation for 30 min, respectively.

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Fig. S9 The charge density difference over (001) crystal face passing the Mn atom in

CsPb0.958Mn0.042Cl3.

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References：

1. J. P. Perdew, K. Burke and M. Ernzerhof, Phys. Rev. Lett. , 1996, 77, 3865-3868.

2. G. Kresse and J. Furthmüller, Phys. Rev. B, 1996, 54, 11169-11186.

3. G. Kresse and D. Joubert, Phys. Rev. B, 1999, 59, 1758-1775.

4. S. L. Dudarev, G. A. Botton, S. Y. Savrasov, C. J. Humphreys and A. P. Sutton, Phys. Rev. B,

1998, 57, 1505-1509.