2D Porous ZnO Nanosheets: One Pot Synthesis with Low Turn-on Field

Document Type: Research Paper


1 Advanced Physics Laboratory, Department of Physics, Savitribai Phule Pune University, Pune, India

2 Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon, India

3 SVKM’s Institute of Technology, Dhule, India

4 Department of Applied Sciences and Humanities, SVKM’s NMIMS, Mukesh Patel School of Technology Management and Engineering, Shirpur Campus, India

5 Nano Materials and Device Laboratory, Department of Applied Physics, Visvesvaraya National Institute of Technology, India


Low turn-on field of 2.3 V/µm was found for the emission current density of 10 µA/cm2 from 2D porous ZnO nanosheets. High current density of 0.76 mA/cm2 was drawn at an applied field of 4.1 V/µm. The observed low turn-on field of porous ZnO nanosheets has been found to be superior to the other ZnO nanostructures reported in the literature. Also, the emission current stability over a period of 3 hr is found to be better. The field emission current density-applied field (J-E) and current-time (I-t) measurements were carried out in all metal field emission microscope by using ‘close proximity’ (also termed as ‘planar diode’). The porous ZnO nanosheets were synthesized by Chemical Bath Deposition (CBD) method at room temperature followed by annealing at 200 oC. The annealed ZnO nanosheets were subjected to structural and morphological analysis prior to the field emission studies. The XRD spectrum of the as-synthesized product reveals formation of crystalline hexagonal phase of ZnO. Simple synthesis route with superior field emission properties indicate the possible use of porous ZnO nanosheets for micro/nanoelectronic devices.


1. Chavan P G, Kashid R V, Badhade S S, Mulla I S, More M A and Joag D S. CdS nanowires: Ultra-long growth and enhanced field emission properties. Vacuum, 2014; 101: 38-45.
2. Nikam P R., Baviskar P K, Sali J V, Gurav K V, Kim J H, Sankapal B R. SILAR coated Bi2S3 nanoparticles on vertically aligned ZnO nanorods: Synthesis and characterizations. Ceram Int 2015; 41:10394.
3. Patil G P, Bagal V S, Suryawanshi S R, Late D J, More M A, Chavan P G. Observation of enhanced field emission properties of Au/TiO2 nanocomposite Appl. Phys. A. 2016; 122:560.
4. Sankapal B, Tripude A, Majumder S, Baviskar P. 1-D electron path of 3-D architecture consisting of dye loaded CdS nanowires: Dye sensitized solar cell J. Alloy Comp. 2015; 651:399.
5. Panda S K, Datta A, Sinha G, Chaudhuri S, Chavan P G, Patil S S, More M A, Joag D S. Synthesis of well-crystalline GaS nanobelts and their unique field emission behaviour. J. Phys. Chem. C 2008; 112:6240.
6. Sonawane N B, Baviskar P K, Ahire R R, Ojha V H, Sankapal B R. Nanonecklace of CdO through simple solution chemistry Mater. Sci. Semicond. Process 2016; 49:81.
7. Bagal V S, Patil G P, Deore A B, Suryawanshi S R, Late D J, More M A, Chavan P G. Surface modification of aligned CdO nanosheets and their enhanced field emission properties. RSC Adv. 2016; 6:41261.
8. Al-Hazmi F, Abdel Aal N, Al-Ghamdi A, Alnowaiser F, Gafer Z H, Al-Sehemi A G, El- Tantawy F, Yakuphanog F J. Facile green synthesis, optical and photocatalytic properties of zinc oxide nanosheets via microwave assisted hydrothermal technique. Electroceram. 2013; 31:324.
9. Dong J Y, Lin C H, Hsu Y J, Lu S Y, Wong D S H. Single-crystalline mesoporous ZnO nanosheets prepared with a green antisolvent method exhibiting excellent photocatalytic efficiencies. Cryst. Eng. Comm. 2012; 14:4732.
10. Lian C L, Wei G L, Yu L, Lin L Z, Jiao H, Wei L. comparison of the field emission characteristics of vertically aligned graphene sheets grown on different SiC substrates. Chin, Phys. B. 2013; 22:107901.
11. Patil G P, Baviskar P K, Bagal V S, Ladhe R D, Deore A B, More M A, Sankapal B R, Chavan P G. Aligned 2D CuSCN nanosheets: a high performance field emitter. RSC Adv. 2016; 6:71958.
12. Zhu M Y, Outlaw R A, Hansen M B, Chen H J. Manosa D M. Enhanced field emission of vertically oriented carbon nanosheets synthesized by C2H2/H2 plasma enhanced CVD. Carbon. 2011; 49:2526.
13. Suryawanshi S R, Kolhe P S, Rout C S, Late D J, More M A. Spectral analysis of the emission current noise exhibited by few layer WS2 nanosheets emitter. Ultramicroscopy. 2015; 149:5 1.
14. Bagal V S, Patil G P, Deore A B, Baviskar P K, Suryawanshi S R, More M A, Chavan P G. High current density and low turn-on field from aligned Cd(OH)2 nanosheets. Chem. Phy. Lett. 2016; 650:7.
15. Kashid R V, Joag D S, Thripuranthaka M, Rout C S, Late D J, More M A. Stable field emission from layered MoS2 nanosheets in high vacuum and observation of 1/f noise. Nanomater. Nanotechnol. 2015; 5:1.
16. Suryawanshi S R, Warule S S, Chaudhari N S, Ogale S B, More M A. Photo-enhanced field emission characteristics of SnS2 nanosheets. AIP Conference Proceedings. 2014; 1591: 342.
17. Naik K K, Khare R, Chakravarty D, More M A, Thapa R, Late D J, Rout C S. Field emission properties of ZnO nanosheet arrays. Appl. Phys. Lett. 2014; 105: 233101.
18. Mittal G, Lahiri I. Recent progress in nanostructured next-generation field emission Devices. J. Phys. D: Appl. Phys. 2014; 47: 323001.
19. Fang X, Bando Y, Gautam U K, Ye C, Golberg D. Inorganic semiconductor nanostructures and their field-emission applications. J. Mater. Chem. 2008; 18:509.
20. Zhai T, Li L, Ma Y, Liao M, Wang X, Fang X, Yao J, Bando Y, Golberg D. One-dimensional inorganic nanostructures: synthesis, field-emission and photodetection. Chem.Soc. Rev. 2011; 40: 2986.
21. Umar A, Akhtar M S, Al-Assiri M S, Al-Hajry A, Algarni H, Romito de Mendonça V, Masuda Y, Kima S H and Rahmanh Q I. Highly porous ZnO nanosheets self-assembled in rosette-like morphologies for dye-sensitized solar cell application. New J. Chem. 2015; 39: 7961.
22. Hynek J, Kalousek V, Zouzelka R, Bezdicka P, Dzik P, Rathousky J, Demel J, Lang K. High photocatalytic activity of transparent films composed of ZnO nanosheets. Langmuir. 2014; 30: 380.
23. Manzari Tavakoli M. H, Ahmadi M, Sabet M. Preparation and Characterization of ZnO Thin Layers with Various Percentages of Gallium Impurities. J Nanostruct. 2017: 7(3): 194.
24. Alaghemand A, Khaghani S, Bihamta M R, Gomarian M, Ghorbanpour M. Green Synthesis of Zinc Oxide Nanoparticles Using Nigella Sativa L. Extract: The Effect on the Height and Number of Branches. J Nanostruct. 2018:8(1): 82.
25. Baviskar P K, Dubal D P, Majumder S, Ennaoui A and Sankapal B R. Basic idea, advance approach: Efficiency boost by sensitization of blended dye on chemically deposited ZnO films. J. of Photochem. and Photobio. A: Chem. 2016; 318: 135.
26. Baviskar P, Ennaoui A and Sankapal B. Influence of processing parameters on chemically grown ZnO films with low cost Eosin-Y dye towards efficient dye sensitized solar cell Sol. Energy. 2014;105:445-454.
27. Baviskar P K, Nikam P R, Gargote S S, Ennaoui A, Sankapal B R. Controlled synthesis of ZnO nanostructures with assorted morphologies via simple solution chemistry. J. Alloys Compd. 2013;551:233.
28. Patil G P, Bagal V S, Mahajan C R, Chaudhari V R, Suryawanshi S R, More M A and Chavan P G. Observation of low turn-on field emission from nanocomposites of GO/TiO2 and RGO/TiO2. Vacuum. 2016; 123: 167.
29. Zhu Y, Apostoluk A, Gautier P, Valette A, Omar L, Cornier T, Bluet J M, Masenelli-Varlot K, Daniele S, Masenelli B. Intense visible emission from ZnO/PAAX (X = H or Na) nanocomposite synthesized via a simple and scalable sol-gel method. Sci Rep. 2016; 6: 23557.
30. Babu K S, Reddy A R, Sujatha C, Reddy K V, Mallika A N Synthesis and optical characterization of porous ZnO. J Adv Ceram 2013;2:260.
31. Wang M, Zhou Y, Zhang Y, Hahn S H, Kim E J. From Zn(OH)2 to ZnO: a study on the mechanism of phase transformation. Cryst. Eng. Comm. 2011; 13: 6024.
32. Song J, Kulinich S A, Yan J, Li Z, He J, Kan C, Zeng H. Epitaxial ZnO nanowire on nanoplate structures as efficient and transferable field emitters. Adv. Mater. 2013; 25: 5750.
33. Zhao C. X, Li Y. F, Zhou J, Li L. Y, Deng S. Z, Xu N. S, Chen J. Large-scale synthesis of bicrystalline ZnO nanowire arrays by thermal oxidation of zinc film: growth mechanism and high-performance field emission. Cryst. Growth Des. 2013; 13: 2897.
34. Young S J, Liu Y H. Enhanced field emission properties of two-dimensional ZnO nanosheets under UV illumination. IEEE J. Select. Topic in Quant. Eelect. 2015; 21.
35. Lai L T, Young S J, Hsing Y, Lin L Z D, Chang S J. UV enhanced field emission properties of ZnO nanosheets with different NaOH concentration. IEEE Trans. on Nanotech. 2015; 14(4).
36. Wei A, Sun X W, Xu C X, Dong Z L, Yu M B, Huang W. Stable field emission from hydrothermally grown ZnO nanotubes. Appl. Phys. Lett. 2006; 88: 213102.
37. Zhu Y W, Zhang H Z, Sun X C, Feng S Q, Xu J, Zhao Q, Xiang B, Wang R M, Yua D P. Efficient field emission from ZnO nanoneedle arrays. Appl. Phys. Lett. 2003; 83: 144.
38. Dewangan K, Patil G P, Kashid R V, Bagal V S, More M A, Joag D S, Gajbhiye N S, Chavan P G, V2O5 precursor-templated synthesis of textured nanoparticles based VN nanofibers and their exploration as efficient field emitter. Vacuum. 2014; 109: 223.
39. Patil G P, Deore A B, Bagal V S, Late D J, More M A, Chavan P G. Low turn-on field and high field emission current density from Ag/TiO2 nanocomposite. Chem. Phy. Lett. 2016;657:167.