Several Orders-of-Magnitude Enhancement of Multiphoton Absorption

Feb 13, 2019 - Several Orders-of-Magnitude Enhancement of Multiphoton Absorption Property for CsPbX3 Perovskite Quantum Dots by Manipulating Halide ...
0 downloads 0 Views 944KB Size
Subscriber access provided by University of Glasgow Library

C: Physical Processes in Nanomaterials and Nanostructures

Several Orders-of-Magnitude Enhancement of MultiPhoton Absorption Property for CsPbX Perovskite Quantum Dots by Manipulating Halide Stoichiometry 3

Avijit Pramanik, Kaelin Gates, Ye Gao, Salma Begum, and Paresh Chandra Ray J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.9b01108 • Publication Date (Web): 13 Feb 2019 Downloaded from http://pubs.acs.org on February 13, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Several Orders-of-Magnitude Enhancement of Multi-Photon Absorption Property for CsPbX3 Perovskite Quantum Dots by Manipulating Halide Stoichiometry Avijit Pramanik, Kaelin Gates, Ye Gao, Salma Begum and Paresh Chandra Ray* Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS, USA; Email:[email protected]; Fax: +16019793674 ABSTRACT: Two-photon absorption (2PA) and three-photon absorption (3PA) processes feature many technologically applications for fluorescence microscopy, photodynamic therapy, optical data storage and so on, Herein, we reveal that the giant 2PA and 3PA properties for all-inorganic CsPbX3 (X = Cl, Br, I, and mixed Cl/Br and Br/I) perovskite quantum dots (PQDs) can be enhanced several orders of magnitudes respectively by simply changing the halide stoichiometry at the X site. Notably, reported data shows excellent 2PA and 3PA properties for CsPbI3 (σ2 ~2.1 × 106 GM and σ3 ~ 1.1X 10-73 cm8 s 3 /photon3 ), which is 2-4orders of magnitude higher than those of conventional red-emitting QDs and 5-7 orders magnitude higher than well documented organic molecules. Experimental results show multi photon absorption (MPA) cross-sections can be adjusted 2-3 orders of magnitude by band gap engineering in a predictable manner, via increasing the Pauling electronegativity of halide. Two photon luminescence imaging data shows that PQDs can be used for very good multi-photon imaging applications. Importantly, reported results provide a new strategy for manipulating MPA properties by halide composition engineering which will be instrumental in the design of next-generation technological devices.

1. INTRODUCTION Multiphoton absorption (MPA) materials simultaneously absorb multiple monochromatic infrared photons and emit a shorter wavelength photon, which offers significant advantages for three dimensional (3D) bio-imaging due to greater spatial confinement and increased penetration depth 1-6.The design of novel two-photon absorption (2PA) and three -photon absorption (3PA) materials have received great attention due to their outstanding applications in multi-photon imaging, two-photon photodynamic therapy, 3D optical data storage and information technology3-11. However, commonly used organic and polymeric MPA material exhibit low multi-photon absorption cross-section, which hampers their use as MPA probe for application3-11. Recently

we and other groups have reported semiconductor quantum dots (QDs) and graphene QDs exhibit superior 2PA compared with traditional organic molecules (>100 GM) and their highest 2PA crosssection is around 104 GM7-11, which is good for optoelectronic devices. Here we report all-inorganic cesium lead halide CsPbX3 (X = Cl, Br, I, and mixed Cl/Br and Br/I) perovskite quantum dots (PQDs) based novel MPA materials with exceptionally high MPA cross-sections (2∼2.1 X 106 GM, where 1 GM = 1 X 10-50 cm4∙s∙photon-1 and 3∼1.1 X 10-73 cm6s2photon-2), whose 2PA and 3PA properties can be enhanced by two and three orders of magnitudes by just simply changing the halide stoichiometry at the X site as.

ACS Paragon Plus Environment

The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 9

solution containing oleylamine (OLA), Oleic acid (OA) and 1-octadecene at high temperature.

Figure 1: TEM image shows monodisperse CsPbX3 PQDs with sizes between (5-7) nm. Inserted photograph shows how single photon fluorescence color varies for CsPbX3 PQDs by manipulation of halide stoichiometry. Due to the low-cost and easy synthesis by wetchemical procedure, as well as extraordinary optical performance, halide perovskite QDs have emerged as one of most promising optoelectronic materials for possible wide range of applications 12-28. Very recently, halide perovskite QDs have been proposed as a material for multiphoton-pumped laser development because they exhibit strong MPA properties 5-6,29-34. In the current letter, we reveal that the giant 2PA and 3PA properties for PQDs can be enhanced by two and fhree orders of magnitudes by just manipulating the halide composition, which provides a new strategy for chemical design of nextgeneration MPA material. Our reported data show that with proper design of halide combination, PQDs can exhibit exceptionally high TPA properties whose 2PA and 3PA coefficients are about two orders of magnitude higher than semiconductor QDs reported in the literature and by five to seven orders of magnitude higher than established organic materials15. 2. RESULTS AND DISCUSSION All the perovskite quantum dots were synthesized via typical hot injection technique under the nitrogen environment, as reported before 12-20. For this purpose, we have injected the precursor Cs-oleate into a PbX2

Figure 2: A) X-ray diffraction patterns for CsPbBr1.5 Cl1.5, which shows it retained the cubic phase throughout the 14-days testing period. B) Xray diffraction patterns for TOP-CsPbI3, which shows it retained the cubic phase throughout the 14 days testing period. C) DLS data show the histogram of the size distribution of the freshly prepared PQDs, which indicates that the size distribution is around 5 ± 1 nm for CsPbCl3, 6 ± 1 nm for CsPbBr3 and 7 ± 1 nm for CsPbl3. To synthesize a series of all inorganic PQDs with different halide stoichiometry at the X site, we have used different halogen ratios. For the synthesis of phase stable CsPbI3 PQDs, we have also added trioctylphosphine TOP−PbI2, using reported method17. Experimental details have been reported in the supporting information. After that, the purified all inorganic PQDs were characterized by highresolution tunneling electron microscopy (HR-TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray powder diffraction (XRD), and dynamic light scattering (DLS), as reported in Figure 1-2 and also in Figure S1-S2 in the supporting information. The

2 ACS Paragon Plus Environment

Page 3 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

element molar ratios of PQDs were determined using inductively coupled plasma–mass spectrometer (ICPMS) data and EDX data.

electronegativity of halides. Figure 1B shows linear relationship netween band gap energy for CsPbX3 and Pauling electronegativity of halides at the X site of PQDs. .Table 1: Bandgap energy from emission spectra, 1P, 2P and 3P cross-sections (measured by Z scan, with ± 10% error) for PQDs over their respective wavelength range.

Figure 3: A) Normalized single-photon induced luminescence spectra from PQDs, 1) CsPbCl3, 2) CsPbCl1.5 Br1.5, 3) CsPbBr3, 4) CsPbBr1.5 I1.5, 5) CsPbBr.5 I2.5, 6) CsPbI3, B) Figure shows how band gap energy for PQDs varies with Pauling electronegativity coefficient for halides at the X site of PQDs. C) Absorption and normalized 1P, 2P, 3P excited PL spectra from CsPbCl3 PQD. D) Absorption and normalized 1P, 2P 3P excited PL spectra from CsPbBr1.5 I1.5 PQD. As shown in Figure S1, the TEM image from freshly prepared CsPbX3 PQDs are highly monodisperse and sizes vary from 5 nm for CsPbCl3 to 7 nm for CsPbI3, which also match very well with the DLS data, reported in Figure 2C. XRD data as reported in Figure 2A-2B, shows that PQDs are retained the cubic phase throughout the testing period. Since the synthesized particle sizes are less than the effective Bohr diameters for CsPbX3 [ CsPbCl3 (5 nm,), CsPbBr3 (7 nm), and CsPbI3 (12 nm)] 12, we have observed excellent quantum confinement for our PQDs. Figure 3 shows the photoluminedcence from PQDs. As reported in Figure 3, the band gap emission for CsPbX3 PQDs covered the entire visible spectrum (400–710) nm and the emission peak position can be manipulated by increasing the Pauling

Typically, electrons in the conduction band minimum (CBM) and holes in the valence band maximum (VBM) are responsible for optical properties of CsPbX312-20. As reported before, for PQDs, VBM originates from the Pb(6s)−X(np) antibonding interactions, and CBM originates from the Pb(6p)−X(np) antibonding interactions 12-20. Since the nature of the band gap is highly influenced by the halide composition, one can easily manipulate the band gap by increasing the Pauling electronegativity of halides The photoluminescence quantum yield (PLQYs ) for all PQDs were measured by the equation 1 12-20, PLQY = N emit/Nabsorb,

(1)

where Nemit and Nabsorb are numbers of emitted and absorbed photons, respectively for PQDs. From the experimental measurement, we have estimated that the PLQY (photoluminescence quantum yield) for our PQDs are about 25% for CsPbCl3, 40% for CsPbCl1.5Br1.5, 60% for CsPbBr3, 75% for CsPbBr1.5I1.5,90% for CsPbBr.5I2,., and 95%, for

3 ACS Paragon Plus Environment

The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

CsPbI3.. As we have reported, the photoluminescence quantum yield (PLQYs) for all PQDs are in the range of 25–95% for CsPbX3 and it can be manipulated by the halide composition by increasing the Pauling electronegativity.

Page 4 of 9

result, PLQY for PQDs will decrease35-40. Several reported experimental data indicate that the lifetimes of trion states for PQDs varies from ∼410 ps for CsPbCl3 to ∼6 ns for CsPbBr3 and ∼33 ns for CsPbI335-40. Since the Auger process for CsPbCl3 is faster than the radiative lifetime of a single e−h pair3540, the PLQY for CsPbCl is lowest. Since the life 3 time is much higher for CsPbI3, we have observed much higher PLQY for CsPbI3. Table 1 reported the single-photon absorption crosssection (σ(1)) for all pQDs. For this purpose, the concentration of PQDs in hexane solution was calibrated by the mass of lead, determined using ICPMS. Reported experimental data clearly show that the 1P optical property as well as 1P cross-section can be manipulated by the halide composition by increasing the Pauling electronegativity. Multi-photon spectroscopy was performed by the two and threephoton excited photoluminescence techniques. Experimental details for two and three-photon absorption experiment have been reported before7,9,1011. In brief, for the measurement of two and threephoton emission from PQDS, we have used a 80 MHz Ti-sapphire laser with 100 fs pulse width as an excitation source7,9,10-11.

Figure 4: A) 2PL spectra from CsPbCl1.5 Br1.5 PQD at 800 nm excitation for several excitation energy levels. B) Figure shows how 2PL intensity from CsPbCl1.5 Br1.5 PQD varies with Iw2 for 800 nm excitation light. C) 3PL spectra from CsPbBr.5 I2.5 PQD at 1420 nm excitation for several excitation energy levels. B) Figure shows how 3PL intensity from CsPbBr.5 I2.5 PQD varies with Iw3 for 1420 nm excitation light. E) Log−log plot of the 2P cross-sections versus bandgap energy for PQDs. F) Log−log plot of the 3P cross-sections versus bandgap energy for PQDs. It is now well documented in literature that the PLQY is determined by the competition between radiative and nonradiative recombination dynamics of photoexcited excitons 35-40. Several recent reports show that nonradiative Auger recombination of trion will compete with radiative recombination35-40. As a

We have used optical parametric amplifier to generate 700-1500 nm excitation wavelength for 2PA and 3PA spectrosocpy. To understand whether any morphological change occurs during multiphoton absorption measurement, we have performed XRD and absorption measurement before and after the measurement. We have found out that the phase transition is negligible within our experimental intensity range. The absorption spectrum also shows that the absorption values remain almost the same during the multiphoton experiment, within our experimental intensity range. Figure 3C shows the normalized 1P, 2P and 3P luminescence spectra from CsPbCl3 PQD using 350, 700, and 1064 nm excitation light. Similarly, Figure 3D shows the normalized 1P, 2P and 3P luminescence spectra from CsPbBr1.5 I1.5 PQD. As reported in Figure 3C and 3D, the normalized PL spectra from CsPbCl3 induced by one-, two-, and three-photon absorption are very identical, which clearly shows very nice size homogeneity. We have also observed same phenomena for all the PQDs we have synthesized. For our experimental observation, we can conclude that that the PQDs excited by either 1P, 2P and 3P absorption will relax to the same lowest excited state. To understand better, we have also performed the excitation intensity

4 ACS Paragon Plus Environment

Page 5 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

dependent 2P and 3P luminescence measurements. As shown in Figures 4A -4D, the quadratic and cubic dependence of the luminescence intensity from CsPbCl1.5Br1.5 PQD at 800 nm excitation and CsPbBr.5 I2.5 PQD at 1420 nm excitation, clearly confirms the two- and three-photon processes.

PQD = FL (FPQD/FFL) (FL PQD) (CFL/CPQD) (2) where F is the observed fluorescence intensity, Φ is the quantum yield is and C is the concentration. Using fluorescein as a reference and equation 2, we have determined the two-photon absorption cross-sections for CsPbBr3 to be 1.4 x 105 GM at 800 nm excitation, as shown Table 1. We have also determined the twophoton absorption using the Z-scan technique 5-6.29-34 as shown in Figure 5A and 5B. For the Z-scans measurement, an 80 MHz Ti-sapphire laser as an excitation source with 100 fs pulse width and 80 MHz repetition rate. Experimental details have been reported in supporting information. For the measurement of 2 and 3 using 700-1500 nm, we have used optical parametric amplifier to generate excitation wavelengths, For 2 and 3 measurement using Z-scan technique, the laser beam was focused onto the 1-mm-thick quartz cuvette containing PQDs by a spherical lens and detected by a Si-based detector. The transmission for open aperture Z-scan was measured using equation (3) 5-6,29-34, Topen (Z) = 1- 1/22 [(αNLI0Leff)]/[1+(z/z0)2] (3)

Figure 5: A) Open-aperture Z-scan curves for CsPbI3 and solvent. B) Open-aperture Z-scan curves for CsPbBr1.5Cl1.5 and CsPbBr1.5I1.5, C) Twophoton florescent microscope images of CsPbBr1.5 Cl1.5 PQD under 800 nm excitation, D) TPF microscope images of CsPbBr3 PQD under 800 nm excitation. E) TPF microscope images of CsPbBr1.5l2.5 PQD under 1064 nm excitation F) TPF microscope images of CsPbBr.5l2.5 PQD under 1064 nm excitation The absolute 2PA and 3PA cross-sections for PQDs were calculated using using fluorescein as a reference, whose 2PA and 3PA cross -sections are known in literature 1-3. 2PA cross section for PQD was determined using the equation 2 1-10,

Where Leff = (1-e-α0L)/α0, with L is the PQD sample thickness, I0 is the on-axis peak intensity. z is the longitudinal displacement of the sample from the focus, and z0 is the Rayleigh diffraction length. After the subtraction of the solvent contribution to the measured overall MPA signal, we have determined the 2PA and 3PA absorption coefficient. As reported in Table 1, σ2 is determined to be 1.8 × 105 GM for CsPbBr3 PQD via Z-scan measurement, which match very well with 2P PL measurement, as well as literature reported values (1.2 × 105 GM for CsPbBr3) 29-34. Table 1 shows σ2 is highest for CsPbI3 (σ2 ~2.1 × 106 GM ) and it is two-orders of magnitude higher than those of conventional red-emitting QDs and five orders magnitude higher than organic molecules. Interestingly, σ2 for CsPbI3 is around two orders of magnitude higher than that of CsPbCl3 (σ2 ~3.8 × 104 GM ), which indicates that 2PA property for PQDs can be manipulated by the halide composition. As shown in Figure 4E, the log−log plot of the 2P cross-sections versus band gap energy is linear with slope is around 6, which indicates that the 2PA coefficient can be increased tremendously through bandgap engineering. As we have reported in Figure 3B, the nature of the band gap is influenced by the

5 ACS Paragon Plus Environment

The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

halide composition and as a result, we have observed the huge enhancement of σ2 values with halide composition. Table 1 shows that σ3 is highest for CsPbI3 (σ3 ~ 1.1 X 10-73 cm8 s 3 /photon3 ) and it is around four-orders of magnitude higher than those of conventional CdSe red-emitting QDs (σ3 ~2.8 X 10-77 cm8 s 3 /photon3) and seven orders magnitude higher than well documented organic molecules (σ3 ~3.7  10-80 cm8 s 3 /photon3 for IPPS). Interestingly, σ3 for CsPbI3 is around three orders of magnitude higher than that of CsPbCl3, which indicates that 3PA property for PQDs can be manipulated by the halide composition. As shown in Figure 4F, the log−log plot of the 3P crosssections versus band gap energy is linear with slope 12, which indicates that 3PA coefficient can be increased tremendously through band gap engineering. . As we have reported in Figure 3B, the nature of the band gap is influenced by the halide composition and as a result, we have observed the huge enhancement of σ3 values with halide composition. Inspired by the excellent 2PA and 3PA properties for PQDs, we attempted to explore the use of PQDs at multiphoton probe for multicolor two-photon imaging. For this purpose, we have performed the deposition of PQDs thin films using spin-coating techniques. For TPL imaging PQD thin film, we have used a Nikon multiphoton microscope. Figure 5C-5F clearly show that thin film PQDs are good two-photon florescent microscope imaging probes. Due to the very high 2PA property for CsPbBr1.5I1.5, we have observed very bright two-photon image from CsPbBr1.5I1.5 thin film with respect to CsPbCl3. Reported data clearly shows that the brightness and two photon imaging color can be altered by simply changing the halide stoichiometry. Although reported data demonstrate that halide PQDs are a highly promising class of nonlinear optical materials for developing next-generation multiphoton imaging applications, due to its intrinsic ionic nature, perovskites are highly sensitive toward moisture. Very poor stability in water for PQDs becomes a main barrier for practical bio-imaging applications. To overcome this, we are planning to synthesize watersoluble perovskites with the use of a fluorocarbon agent or (3-aminopropyl) triethoxysilane (APTES) or by incorporation the polymer, as reported recently 4142.

Page 6 of 9

3. CONCLUSION In conclusion, our findings reveal that the family of halide perovskite PQDS possesses outstanding MPA properties, whose 2PA and 3PA coefficients can be enhanced by two and three orders of magnitudes by simply changing the halide stoichiometry. Reported data shows σ2 is highest for CsPbI3(σ2 ~2.1 × 106 GM ) and it is two-orders of magnitude higher than those of conventional red-emitting QDs and five orders magnitude higher than organic molecules. Interestingly, σ2 for CsPbI3 is around two orders of magnitude higher than that of CsPbCl3 (σ2 ~3.8 × 104 GM ). On the other hand, experimental data indicate σ3 is highest for CsPbI3 (σ3 ~ 1.1 X 10-73 cm8 s 3 /photon3) and it is around four-orders of magnitude higher than those of conventional CdSe red-emitting QDs and seven orders magnitude higher than well documented organic molecules. Our experimental results show that MPA properties for PQDs can be adjusted by band gap engineering in a predictable manner, via increasing the Pauling electronegativity of halides. The log−log plot of the 2P cross-sections versus band gap energy is linear with slope is around 6 and the log−log plot of the 3P cross-sections versus band gap energy is linear with slope 12, which indicates that the 2PA and 3PA coefficient can be increased tremendously through bandgap engineering. 4. SUPORTING INFORMATIONS: Detailed synthesis, characterization of PQDs and other experiments are available as a supporting information. This information is available free of charge via the Internet at http://pubs.acs.org/ 5. ACKNOWLEDGEMENTS Dr. Ray thanks NSF-PREM grant # DMR-1205194, DOD grant # W911NF-16-1-0505, NSF CREST grant # 1547754, NSF RISE grant # 1547836 for their generous funding.

5. REFERENCES 1. Zhang, K. Y.; Yu, Q.; Wei, H.; Liu, S.; Zhao, Q.; Huang, W. Long-Lived Emissive Probes for Time-Resolved Photoluminescence Bioimaging and Biosensing. Chem. Rev. 2018, 118, 1770– 1839 2. Schlawin, F.; Dorfman, K. E.; and Mukamel, S.;

6 ACS Paragon Plus Environment

Page 7 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Entangled Two-Photon Absorption Spectroscopy, Acc. Chem. Res., 2018, 51, 2207–2214 3. Staude, I.; Schilling, J. Metamaterial-inspired silicon nanophotonics. Nat. Photonics 2017, 11, 274 4. Zhang, K. Y.; Yu, Q.; Wei, H.; Liu, S.; Zhao, Q.; Huang, W. Long-Lived Emissive Probes for Time-Resolved Photoluminescence Bioimaging and Biosensing. Chem. Rev. 2018, 118, 1770– 1839 5. Chen, W. Q.; Bhaumik, S.; Veldhuis, S. A.; Xing, G. C.; Xu, Q.; Gratzel, M.; Mhaisalkar, S.; Mathews, N.; and Sum, T. C.; Giant five-photon absorption from multidimensional core-shell halide perovskite colloidal nanocrystals, Nat. Commun. 2017, 8, 15198. 6. Ferrando, A.; Martinex-Pastor, J. P.; Suarez, Toward Metal Halide Perovskite Nonlinear Photonics, J. Phys. Chem. Lett., 2018, 9, 5612–5623 7. Vangra A,; Pramanick, A.; Gao Y.; Gates, K.; Begum, S.; Ray, P. C.; Fluorescence Resonance Energy Transfer Based Highly Efficient Theranostic Nanoplatform for Two-Photon Bioimaging and Two-Photon Excited Photodynamic Therapy of Multiple Drug Resistance Bacteria, ACS Appl. Bio Mater., 2018, 1, 298–309 8. Yuan, F. L.; Yuan, T.; Sui, L. Z.; Wang, Z. B.; Xi, Z. F.; Li, Y. C.; Li, X. H.; Fan, L. Z.; Tan, Z. A.; Chen, A. M.;Jin, M. X.; Yang, S. H. Engineering Triangular Carbon Quantum Dots with Unprecedented Narrow Bandwidth Emission for Multicolored LEDs. Nat. Commun. 2018, 9, 2249 9. Sinha, S. S.; Jones, S.; Demeritte, T.; Chavva, S. R.; Shi, Y.; Burrell, J.; Pramanik, A.; Ray, P.C. Mult imodal Nonlinear Optical Imaging of Live Cells Using Plasmon-Coupled DNA-Mediated Gold Nanoprism Assembly J. Phys. Chem. C 2016, 120, 4546– 455 10. Ray, P. C. Size and Shape Dependent Second Order Nonlinear Optical Properties of Nanomaterials and their Application in Biological and Chemical Sensing Chem. Rev. 2010, 110, 5332– 5365 11. Pramanik, A.; Chavva, S. R.; Fan, Z.; Sinha, S.; Nellore, B. P.; Ray, P. C. Extremely High Two-PhotonAbsorbing Graphene Oxide for Imaging of Tumor Cells in the Second Biological Window J. Phys. Chem. Lett. 2014, 5, 2150– 2154 12. Protesescu, L.; Yakunin, S.; Bodnarchuk, M. I.; Krieg, F.; Caputo, R.; Hendon, C. H.; Yang, R. X.; Walsh, A.;Kovalenko, M. V. Nanocrystals of cesium lead halide perovskites (CsPbX3, x = Cl, Br, and I): Novel optoelectronic materials showing

13.

14.

15.

16.

17.

18.

19. 20.

21. 22.

bright emission with wide color gamut. Nano Lett. 2015, 15, 3692– 3696 Yang, W. S.; Park, B.-W.; Jung, E. H.; Jeon, N. J.; Kim, Y. C.; Lee, D. U.; Shin, S. S.; Seo, J.; Kim, E. K.;Noh, J. H.Iodide Management in Formamidinium-Lead-Halide–Based Perovskite Layers for Efficient Solar Cells. Science 2017, 356, 1376– 1379 Kovalenko, M. V.; Protesescu, L.; Bodnarchuk, M. I. Properties and Potential Optoelectronic Applications of Lead Halide Perovskite Nanocrystals. Science 2017, 358, 745– 750 Huang, L.; Gao, Q.; Sun, L.-D.; Dong, H.; Shi, S.; Cai, T.; Liao, Q.; Yan, C.-H. CompositionGraded Cesium Lead Halide Perovskite Nanowires with Tunable Dual-Color Lasing Performance. Adv. Mater. 2018, 30,1800596, Pan, J.; Shang, Y.; Yin, J.; De Bastiani, M.; Peng, W.; Dursun, I.; Sinatra, L.; El-Zohry, A. M.; Hedhili, M. N.;Emwas, A.-H.; Mohammed, O. F.; Ning, Z.; Bakr, O. M. Bidentate LigandPassivated CsPbI3 Perovskite Nanocrystals for Stable Near-Unity Photoluminescence Quantum Yield and Efficient Red Light-Emitting Diodes. J. Am. Chem. Soc. 2018, 140, 562– 565, Liu, F.; Zhang, Y.; Ding, C.; Kobayashi, S.; Izuishi, T.; Nakazawa, N.; Toyoda, T.; Ohta, T.; Hayase, S.;Minemoto, T.; Yoshino, K.; Dai, S.; Shen, Q. Highly Luminescent Phase-Stable CsPbI3 Perovskite Quantum Dots Achieving Near 100% Absolute Photoluminescence Quantum Yield. ACS Nano 2017, 11, 10373–10383 Xing, J.; Zhao, Y.; Askerka, M.; Quan, L. N.; Gong, X.; Zhao, W.; Zhao, J.; Tan, H.; Long, G.; Gao, L.;Yang, Z.; Voznyy, O.; Tang, J.; Lu, Z.-H.; Xiong, Q.; Sargent, E. H. Color-stable highly luminescent sky-blue perovskite light-emitting diodes. Nat. Commun. 2018, 9, 3541 Kamat, P. V. Hybrid Perovskites for Multijunction Tandem Solar Cells and Solar Fuels. A Virtual Issue. ACS Energy Lett. 2018, 3, 28– 29 Becker, M. A.; Vaxenburg, R.; Nedelcu, G.; Sercel, P. C.; Shabaev, A.; Mehl, M. J.; Michopoulos, J. G.;Lambrakos, S. G.; Bernstein, N.; Lyons, J. L.Bright Triplet Excitons in Caesium Lead Halide Perovskites. Nature 2018, 553, 189– 193 Seth, S.; Samanta, A. Photoluminescence of ZeroDimensional Perovskites and Perovskite-Related Materials. J. Phys. Chem. Lett. 2018, 9, 176– 183, Xiao, Z.; Zhao, L.; Tran, N. L.; Lin, Y. L.; Silver, S. H.; Kerner, R. A.; Yao, N.; Kahn, A.; Scholes, G. D.;Rand, B. P. Mixed-Halide Perovskites with

7 ACS Paragon Plus Environment

The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

23.

24.

25.

26. 27.

28.

29.

30.

31.

32.

Stabilized Bandgaps. Nano Lett. 2017, 17, 6863– 6869 Almutlaq, J.; Yin, J.; Mohammed, O. F.; Bakr, O. M. The Benefit and Challenges of ZeroDimensional Perovskites. J. Phys. Chem. Lett. 2018, 9, 4131– 4138 Balakrishnan, S. K.; Kamat, P. V. AuCsPbBr3 Hybrid Architecture: Anchoring Gold Nanoparticles on Cubic Perovskite Nanocrystals. ACS Energy Lett. 2017, 2, 88– 93 Akkerman, Q. A.; Raino, G.; Kovalenko, M. V.; Manna, L. Genesis, challenges and opportunities for colloidal lead halide perovskite nanocrystals. Nat. Mater. 2018, 17, 394– 405 Zhang, Q.; Yin, Y. All-Inorganic Metal Halide Perovskite Nanocrystals: Opportunities and Challenges. ACS Cent. Sci. 2018, 4, 668– 679 Dong, Y.; Qiao, T.; Kim, D.; Parobek, D.; Rossi, D.; Son, D. H. Precise Control of Quantum Confinement in Cesium Lead Halide Perovskite Quantum Dots via Thermodynamic Equilibrium. Nano Lett. 2018, 18,3716– 3722 Yao, J.-S.; Ge, J.; Han, B.-N.; Wang, K.-H.; Yao, H.-B.; Yu, H.-L.; Li, J.-H.; Zhu, B.-S.; Song, J.Z.; Chen, C.;Zhang, Q.; Zeng, H.-B.; Luo, Y.; Yu, S.-H. Ce3+-Doping to Modulate Photoluminescence Kinetics for Efficient CsPbBr3 Nanocrystals Based Light-Emitting Diodes. J. Am. Chem. Soc. 2018, 140, 3626– 3634 Wang, Y.; Li, X.; Zhao, X.; Xiao, L.; Zeng, H.; Sun, H. Nonlinear absorption and low-threshold multiphoton pumped stimulated emission from allinorganic perovskite nanocrystals. Nano Lett. 2016, 16, 448– 453 Chen, J.; Zidek, K.; Chabera, P.; Liu, D.; Cheng, P.; Nuuttila, L.; Al-Marri, M. J.; Lehtivuori, H.;Messing, M. E.; Han, K.; Zheng, K.; Pullerits, T. Sizeand wavelength-dependent twophoton absorptioncross-section of CsPbBr3 perovskite quantum dots. J. Phys. Chem. Lett. 2017, 8, 2316– 2321 Chen, J.; Chabera, P.; Pascher, T.; Messing, M. E.; Schaller, R.; Canton, S.; Zheng, K.; Pullerits, T.Enhanced size selection in two-photon excitation for CsPbBr3 perovskite nanocrystals. J. Phys. Chem. Lett. 2017, 8, 5119– 5124 Nagamine, G.; Rocha, J.O.; Bonato, L.G.; Nogueira, A.F.; Zaharieva, Z.; Watt, A.A.R.; Brito Cruz, C.H.;Padilha, L.A. Two-Photon Absorption and Two-Photon-Induced Gain in Perovskite Quantum Dots, J. Phys. Chem. Lett. 2018, 9, 3478– 3484

Page 8 of 9

33. Zou, S.; Yang, G.; Yang, T.; Zhao, D.; Gan, Z.; Chen, W.; Zhong, H.; Wen, X.; Jia, B.; Zou, B. Template-Free Synthesis of High-Yield FeDoped Cesium Lead Halide Perovskite Ultralong Microwires with Enhanced Two-Photon Absorption. J. Phys. Chem. Lett. 2018, 9, 4878– 4885 34. Li, L.; Shang, X.; Wang, S.; Dong, N.; Ji, C.; Chen, X.; Zhao, S.; Wang, J.; Sun, Z.; Hong, M.Bilayered Hybrid Perovskite Ferroelectric with Giant TwoPhoton Absorption. J. Am. Chem. Soc. 2018, 140,6806– 6809 35. Yarita, N.; Tahara, H.; Ihara, T.; Kawawaki, T.; Sato, R.; Saruyama, M.; Teranishi, T.; Kanemitsu, Y. Dynamics of Charged Excitons and Biexcitons in CsPbBr3 Perovskite Nanocrystals Revealed by Femtosecond Transient-Absorption and Single-Dot Luminescence Spectroscopy. J. Phys. Chem. Lett. 2017, 8, 1413−1418 36. Li, B; Huang, H; Zhang, G; Yang, C; Guo, W; Chen, R; Qin, C; Gao, Y; Biju, V; Rogach, AL’ Xiao, L; Jia, S;, Excitons and Biexciton Dynamics in Single CsPbBr3 Perovskite Quantum Dots, J. Phys. Chem. Lett., 2018, 9, 6934–6940. 37. Seth, S.; Ahmed, T.; Samanta, A,; Photoluminescence Flickering and Blinking of Single CsPbBr3 Perovskite Nanocrystals: Revealing Explicit Carrier Recombination Dynamics, J. Phys. Chem. Lett., 2018, 9, 7007–7014. 38. Yin, C.; Chen, L.; Song, N.; Lv, Y.; Hu ,F.; Sun, C.; Yu, W.; Zhang, C.; Wang, X.; Zhang, Y, and Xiao, M; Bright-Exciton Fine-Structure Splittings in Single Perovskite Nanocrystals, Phys. Rev. Lett. 2017, 119, 026401 39. Ahumada-Lazo, R.; Alanis, J. A.; Parkinson, P.; Binks, D. J.; Hardman, J. O. S.; Griffiths , J. T.; Rivarola, R. W. F.; Humphrey, C. J.; Ducati , C,; and Davis, N. J. K. , Emission Properties and Ultrafast Carrier Dynamics of CsPbCl 3 Perovskite Nanocrystals, J. Phys. Chem. C, 2019, 123, 2651– 2657 40. Vickers, E. T.; Graham, T. A.; Chowdhury, A. H.; Bahrami, B.; Dreskin, B. W.; Lindley, S.; Naghadeh, S. B.; Qiao, Q.; and Zhang, J. Z.; Improving Charge Carrier Delocalization in Perovskite Quantum Dots by Surface Passivation with Conductive Aromatic Ligands, ACS Energy Lett., 2018, 3, 2931–2939 41. Zheng, L.; Ma, Y.; Xiao, L.; Zhang, F.; Wang, Y.; Yang, H.; Water-Soluble Polymeric Interfacial Material for Planar Perovskite Solar Cells, ACS Appl. Mater. Interfaces, 2017, 9, 14129–14135

8 ACS Paragon Plus Environment

Page 9 of 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

42. Ding, N.; Zhou, D,; Sun, X,; Xu, W.; Xu, H,; Pan, G,; Li, D,; Zhang, S.; Dong. B.; Song, H.; Highly stable and water-soluble monodisperse CsPbX3/SiO2nanocomposites for white-LED and cells imaging, Nanotechnology, 2018 24, 29, 345703.

9 ACS Paragon Plus Environment