Electronic Supplementary Material (ESI) for RSC Advances. This journal is © The Royal Society of Chemistry 2020

Supporting Information for

Stable green and red dual-emissions in the single all-inorganic

halide-mixed perovskites microsheet

Manyi Zhong1, Zhuang Zhao1, Yuan Luo1, Fang Zhou3,*, Yuehua Peng1, Yanling Yin1,

Weichang Zhou1,2,*, Dongsheng Tang1,2

1 School of Physics and Electronics, Key Laboratory of Low-dimensional Quantum

Structures and Quantum Control of Ministry of Education, Normal University,

Changsha 410081, People’s Republic of

2 Key Laboratory for Matter Microstructure and Function of Hunan Province,

Synergetic Innovation Center for Quantum Effects and Application, Hunan Normal

University, 410081, People’s Republic of China

3 Department of Basic Course, Hunan Police Academy, Changsha 410138, People’s

Republic of China

* Corresponding Author.

E-mail: [email protected] (F. Z.), [email protected] (W. Z.) Fig. S1 (a) Synthesis schematic diagram of CsPbBrxI3-x microsheets. (b) Optical

image of as-synthesized CsPbBrxI3-x microsheets. (c-d) SEM of single CsPbBrxI3-x microsheet with different magnification. (a) 1 min 2 min 3 min 5 min 7 min 10 min Experiment date of Br-rich peak Lorentz peak 1 contribution Lorentz peak 2 contribution ) .

u Lorentz function fit . a ( y t i s n e t n I

Photon Energy (eV)

(b) 1 min 2 min 3 min 5 min 7 min 10 min

Experiment date of I-rich peak Gaussian peak 1 contribution Gaussian peak 2 contribution ) . u

. Gaussian function fit a (

y t i s n e t n I

Ph oton Energy (eV)

Fig. S2 (a) Lorentz decomposition of PL spectra in the range of 2.21−2.46 eV upon 1,

2, 3, 5, 7 and 10 min laser excitation. (b) Gaussian decomposition of PL spectra in the range of 1.65-2.05 eV upon 1, 2, 3, 5, 7 and 10 min laser excitation. All fitting curves exhibit two peaks. 10000 800 (a) 1 min (b) 1 min 2 min 700 2 min 8000 3 min 3 min 600 4 min 4 min ) ) . .

u 5 min u . 5 min

. 500

a 6000 a ( ( 6 min 6 min y y t t i 400 i s s n n e e t 4000 t

n 300 n I I 200 2000 100

0 0 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 Photon Energy (eV) Photon Energy (eV)

(c) 0.2 mW 0.02 mW 0.002 mW Experiment date of I-rich peak Gaussian peak 1 contribution (1.7745 eV) Gaussian peak 2 contribution (1.7795 eV) ) . Gaussian function fit u . a (

y t i s n e t n I

Photon Energy (eV)

Fig. S3 (a,b) PL spectra collected at different illumination time under the laser power

of 0.3 mW and 0.03 mW (λ=355 nm) of the same CsPbBrxI3-x micro/nanosheet in Fig.

2a. (c) Gaussian decomposition of the PL spectra in the range of 1.65−2 eV with different laser power. 60000 100000 (a) 1.6 mW (b) 0.5 mW 50000 0.05 mW×2 α=0.69 ) .

) 0.005 mW×20 . u 10000 . α=0.57 u 40000 . a ( a

( y y t t i i s s

30000 n n e e t t n n i I 1000

L

L 20000 P P PL intensity of I-rich peak 1.776 eV 10000 PL intensity of I-rich peak 1.781 eV 100 Power function Fit Power function Fit 0 1.7 1.8 1.9 2.0 2.1 2.2 1 10 100 Photon Energy (eV) Laser power (μW)

(c) 0.005 mW 0.05 mW 0.5 mW 1.6 mW

Experiment date of I-rich peak Gaussian peak 1 contribution 1.776 eV

) Gaussian peak 2 contribution 1.781 eV . u .

a Gaussian function fit (

y t i s n e t n I

Photon Energy (eV)

Fig. S4 (a) Power-dependent PL spectra under excitation of 532 nm CW laser. (b)

Log-log plot of PL intensity versus laser intensity for the I-rich peaks extracted from

Fig. S4a (points). The solid lines are fitting curves using power function. (c) Gaussian decomposition of PL spectra in the range of 1.65−2 eV under different laser power. 100000 60000 (a) Experiment date of Br-rich peak 2.302 eV (b) Power function Fit Experiment date of Br-rich peak 2.353 eV 50000 Power function Fit 10000 ) ) . . u u .

. 40000 a a ( (

y y t t i

i 0.64mW s

s 30000 α=1.7 α=1.75 n

n 1000 0.2 mW e e t t n n i

I 0.02 mW×8

20000 L

0.002 mW×100 P 10000 100

0 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 1 10 100 Photon Energy (eV) Laser power (μW)

100000 (c)

10000 ) . u . α=0.93 a

( α=0.925

y t i

s 1000 n e t n i

L P 100 Experiment date of I-rich peak 1.79 eV Power function Fit Experiment date of I-rich peak 1.82 eV Power function Fit 10 1 10 100 Laser power (μW)

Fig. S5 (a) Power-dependent PL spectra of another selected single CsPbBrxI3-x micro- sheet different from the one in main text. Inset is corresponding optical image. (b,c)

Log-log plot of PL intensity versus laser power for Br-rich and I-rich peaks extracted

from Fig. S5a, respectively. (a) 1 min 4 min 7 min 10 min

Experiment date of Br-rich peak Peak Fit ) . u . a ( y t i s n e t n I

Photon Energy (eV) (b) 1 min 4 min 7 min 10 min Experiment date of I-rich peak Gaussian peak 1 contribution Gaussian peak 2 contribution ) . Gaussian function fit u . a (

y t i s n e t n I

Photon Energy (eV)

Fig. S6 (a) Gaussian decomposition of PL spectra in the range of 2.15−2.45 eV under illumination time of 1, 4, 7 and 10 min. (b) Gaussian decomposition of PL spectra in the range of 1.65−2.1 eV under illumination time of 1, 4, 7 and 10 min. Table S1. The corresponding lifetime constants and amplitudes of Br-rich peaks.

휏 1 휏 2 A1 퐵푟 (ns) A2 퐵푟 (ns)

1 min 40.6% 5.75 59.4% 1.33

4 min 64.4% 4.987 35.6% 1.39

7 min 66.1% 6.649 33.9% 1.518

10 min 65.9% 7.546 34.1% 1.881

Table S2. The corresponding lifetime constants and amplitudes of I-rich peaks.

휏1 휏2 휏3 A1 퐼 (ns) A2 퐼(ns) A3 퐼(ns)

1 min 240.6% 4.337 -128.2% 3.655 -12.4% 0.49

4 min 198.9% 6.374 -69.3% 7.452 -29.6% 4.67

7 min 104.3% 7.26 -11.5% 10.4 7.2% 3.21

10 min 95.2% 7.72 -8.8% 11.2 13.6% 2.44 (a) -150℃ -125℃ -100℃ -75℃ -50℃ -25℃

Experiment date of Br-rich peak Lorentz peak 1 contribution ) .

u Lorentz peak 2 contribution . a (

Lorentz function fit y t i s n e t n I

Photon Energy (eV) (b) -150℃ -125℃ -100℃ -75℃ -50℃ -25℃

Experiment date of I-rich peak Gaussian peak 1 contribution

) Gaussian peak 2 contribution . u . Gaussian function fit a (

y t i s n e t n I

Photon Energy (eV)

Fig. S7 (a) Lorentz decomposition of PL spectra in the range of 2.27−2.42 eV at

temperature of −25 oC, −50 oC, −75 oC, −100 oC, −125 oC and −150 oC. (b) Gaussian decomposition of PL spectra in the range of 1.75−2.2 eV at temperature of −25 oC,

−50 oC, −75 oC, −100 oC, −125 oC and −150 oC. All the fitting curves exhibit two

peaks.