polymerization approach to hybrid 2d black phosphorus

Materials 22-26 October Bologna

In situ polymerization approach to hybrid 2D black phosphorus/polymer

materials: a novel strategy for optoelectronic device fabrication

Elisa Passagliaa*,

Francesca Cicognaa, Serena Coiaia, Federica Costantinoa, Giulia Lorenzettia, Stefano Legnaiolia, Silvia Borsacchia, Marco Geppib, Francesca Telesioc, Stefan Heunc, Andrea Iencod, Manuel Serrano-

Ruizd, Maria Caporalid, Maurizio Peruzzinid

[email protected]

a Istituto di Chimica dei Composti Organometallici (CNR-ICCOM), SS Pisa

b Dipartimento di Chimica e Chimica Industriale (DCCI)

c NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore

d Istituto di Chimica dei Composti Organometallici (CNR-ICCOM), Fi


• It is a semiconductor with thickness-dependent band gap: as the thickness decreases by exfoliation, the band gap gradually increases relying the nanosheets as ideal platform for electronic and optoelectronic devices.

• It shows prominent electron transport capability and low thermal conductance both in the zig-zag and armchair lattice direction and has a really good thermal resistance, resulting in a very promising material for thermoelectric applications.

• It is more flexible than graphene or MoS2, with modulus values strongly depending on the structural anisotropy, opening the way to strain engineering applications.

L. Kou, C. Chen, S.C. Smith, J. Phys. Chem. Lett. 2015, 6, 2794-2805

Phosphorene (2D bP) is the single- or few-layer form of black phosphorus (bP), the most stable allotrope of phosphorus with a

puckered structure in the armchair direction.


(http://www.wikiwand.com/en/Phosphorene)Han Liu, Adam T. Neal,Zhen Zhu, Zhe Luo, Xianfan Xu,David Toma´ nek, and Peide D. Ye ACS Nano, 8, 4033 (2014)

• by cleavage with tape

Atomic force microscopy image of a single-layer phosphorene crystal with the measured thickness of ≈0.85 nm.

• by liquid or solvent exfoliation

Right: TEM image of single phosphorene layer. Left: photos of A) bulk BP and B) phosphorene dispersed in NMP and water

http://www.wikiwand.com/en/Phosphorene


Intrinsic instability in ambient atmosphere, undergoing to severe degradation bymoisture and oxygen and light (UV) upon prolonged air exposition. The formation ofsurface oxidised species is responsible for a measurable increase in surface roughnessand degradation, with severe detriment of performances of phosphorene-basedelectronic devices that are prepared and measured in air.

“To prevent the single-layer phosphorene reacting with the environment, it is covered by PMMA layer during experiments”.

Han Liu, Adam T. Neal,Zhen Zhu, Zhe Luo, Xianfan Xu,David Toma´ nek, and Peide D. Ye ACS Nano, 8, 4033 (2014)A. Castellanos-Gomez, L. Vicarelli, E. Prada, J. O. Island, K.L. Narasimha-Acharya, S. I. Blanter, D. J. Groenendijk, M. Buscema, G. A. Steele, J. V. Alvarez, H.

W. Zandbergen, J. J. Palacios, H. S .J. van der Zant, 2D Materials, 2014, 1, 025001

Sequence of optical images acquired at different times after the transfer of the exfoliated black phosphorus flakes. The sequenceshows how one hour after the transfer some droplet-like structures become visible on the surface of the flakes and how theykeep growing when the samples are kept in air. On the right enlargement (a) and Raman spectra (b) of different portions showingthe disappearance of diagnostic signals


To directly obtain 2D bP by exfoliation during the polymer-based hybrids preparation

To preserve the 2D bP structure and properties from aging and environmental damage by

embedding in polymer phaseTo obtain polymer-based materials directly

suitable for devices fabrication


DMSO

CHCl3

under N2

MeOH

N2

drop wise

Hybrid

PMMA

solution

CHCl3/DMSO

PMMA

solutionMeOH

drop wise

Hybrid

AIBN, T=70°C

HybridIn-situ polymerization

PMMAPMMA_bP_A

PMMA_C_blankPMMA_bP_C

PMMA_B_blankPMMA_bP_B


3600 3000 2400 1800 1200 600

Tra

sm

itta

nce

a.u

Wavenumber (cm-1)

PMMA

PMMA_C_blank

PMMA_bP_C

300 600 900 1200 1500 1800 2100 2400 2700 3000

PMMA_bP_B

PMMA_bP_C

PMMA_bP_A

PMMA_C_blank

Inte

sity (

a.u

)Raman Shift (cm

-1)

PMMA

• The structure of PMMA is mantained also when produced by in situ polymerization• The presence of bP was proved for all the hybrids


• Comparable or lower MW data forhybrids obtained by method A and Bowing to prolonged sonication

• Higher values of MW for PMMA_bP_Cwith respect to the blank run suggestingto growing of polymer chains in a“confined space” generating reallyentangled macro-aggregates as seen byAFM

• Thermal features show increased Tg andsimilar degradation temperatures for allthe hybrids

Sample 𝑴𝒏 (D) 𝑴𝒘 (D) Tg (°C) Tonset(°C) Tinfl(°C)

PMMA 52,000 101,000 105.0 264 290-387

PMMA_bP_A 56,000 97,000 115.6 279 294-394

PMMA_B_blank 57,000 90,000 108.7 267 285-390

PMMA_bP_B 49,000 80,000 115.1 280 294-395

PMMA_C_blank 45,000 103,000 120.6 272 287-381

PMMA_bP_C 58,000 198,000 121.0 269 293-372


10 mm 10 mm 10 mm

10 mm 10 mm 10 mm

10 mm10 mm

A

B

C

10 mm

• PMMA_bP_A : good homogeneous distribution of tiny particles (below 1 mm) resembling the bPn and a really small amount of larger aggregates

• PMMA_bP_B : very large inclusions in all the portions investigated• PMMA_bP_C : finer dispersion of bP since tiny particles and flakes, homogeneously

distributed, were observed and only a small fraction of larger aggregates (of several mm)


10 mm

(a)

10 mm

(b)

(c)

500 1000 1500 2000 2500 3000

inte

nsity a

.u.

Raman shift cm-1

(a)

(b)

(c)

300 350 400 450 500 550 600 650

C-O in plane

Bending (599cm-1)

Ag

2

• PMMA_bP_C contains the higher content of 2D bP which is not oxidized

H3PO4/H3PO3

(𝑷O)(OP)(OH)2

bP 6%

PMMA_bP_A

PMMA_bP_B

PMMA_bP_C


4000 3500 3000 2500 2000 1500 1000

T a

.u.

cm-1

PMMA_C_Blank

PMMA_C_Blank after irradiation

PMMA_bP_C

PMMA_bP_C after irradiation

UV

• Polymer matrix results oxidized

high pressure Mercury Lamp

with a power of 400W

http://www.google.it/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwi-lIWU2svOAhXLNxQKHY9pBW8QjRwIBw&url=http://www.hikari-trading.com/honle/honle1.html&bvm=bv.129759880,d.d24&psig=AFQjCNHGdsQjV-yJDIfWuyV3Ib9jp06Bkw&ust=1471635105223594


(a): large aggregates (several microns) (b): tiny aggregates or nanoflakes

• 2D bP nanoflakes survive to prolonged irradiation


AIBN, T=70°C

HybridIn-situ polymerization

NVP

Sty

• Different hybrids can be successfully prepared starting from other vinyl monomers

After spin-coating onto SiO2 wafer prepared after about one year since

hybrid preparation


Schematic representation of bP nanosheets embedded in PMMA, on a Si/SiO2

substrate and fabricated device. Identified flake (a) with Raman spectrum (b); device (c) and Raman spectrum on the device (d). bP diagnostic signals were still present after 3 months

200 300 400 500 6000.0

0.5

1.0

1.5

2.0

2.5

3.0

Inte

nsity/I

nte

nsity o

f S

i p

ea

k (

a.u

.)

Raman Shift (cm-1)

200 300 400 500 6000

2

4

6

8

10

12

Inte

nsity/I

nte

nsity o

f S

i p

ea

k (

a.u

.)

Raman Shift (cm-1)

(a) (c)

(b) (d)

Stable 2D bPcomposite powder Stable 2D bP

composite anisole solution

Without the need of glove box or inert atmosphere


-100 -80 -60 -40 -20 0 20 40 60 80 1004

6

8

10

12

14

16

18

20

22

24

I sd (

nA

)

Vg (V)

-1 0 1-10

0

10

I sd(n

A)

Vsd

(mV)

-1.0 -0.5 0.0 0.5 1.0-80

-60

-40

-20

0

20

40

60

80

I sd (

nA

)

Vsd (mV)

R=14.8kOhm

Current (I) versus voltage (V) characteristics of the device at room temperature. Resistance R = 14.8 kOhm.

Low temperature measurements at 4.2 K. Source-drain current as a function of gate voltage for Vsd = 1 mV shows p-type behaviour. Field-effect mobility 35 cm2 V-1 s-1. Isd

vs. Vsd curve, shown in the inset, gives 108 kOhm.

• The device shows a resistivity and carrier mobility characteristic ofblack phosphorus, as well as the p-type behaviour upon gate voltagemodulation expected for this material proving that the hybrid is asuitable platform for device applications.


• Hybrid materials were obtained by dispersing black phosphorus nanoflakes in polymermatrices with the aim of promoting the exfoliation of bP while protecting the generatednanostructures from oxidation.

• The procedure comprising the Liquid Phase Exfoliation (LPE) in the vinyl monomer followed byin situ radical polymerization provided hybrid polymer-based materials with good dispersionof bP and protected bP nanoflakes.

• The monomer LPE seems capable of promoting the exfoliation of bP and the following in situpolymerization encapsulates the nanoflakes, preserving their structure.

• Really important, once incorporated in the polymer, bPnanoflakes showed an improved stability even when thecomposites were stored in air, at room temperature inambient conditions or UV irradiated.

• These results widen the application possibilities of thisreally promising nanofiller once polymer-coated,particularly in making easier the design of different devices(for optoelectronic applications and/or gas/chemicalsensing).

Passaglia et al., RSC Adv., 6, 53777-53783 (2016);Passaglia et al., Chem. Mat. 30, 2036, (2018); Telesio et al., Nanotechnology 29, 295601, (2018);


European Research Council found the project PHOSFUN “Phosphorene functionalization: a new platform for advanced multifunctional materials” (Grant Agreement No. 670173) through an ERC Advanced Grant to MP

Federica CostantinoPresent positionPhD/Fellow@IIT

Francesca CicognaResearcher@CNR-ICCOM

Serena CoiaiResearcher@CNR-ICCOM

Stefano LegnaioliResearcher@CNR-ICCOM

Giulia LorenzettiPost-Doc @CNR-ICCOM

Silvia BorsacchiResearcher@CNR-ICCOM

Marco GeppiProf @DCCI-UNIPI

Maurizio PeruzziniDirector of CNR-DSCTM

Francesca TelesioPost-Doc @CNR-NANO

Stefan HeunSenior Researcher

@CNR-NANO

Andre IencoResearcher@CNR-ICCOM

Manuel Serrano RuizResearcher@CNR-ICCOM

Maria CaporaliResearcher@CNR-ICCOM

polymerization approach to hybrid 2d black phosphorus

Documents