Pulsed Laser Deposition of Photoresponsive Two-Dimensional GaSe Nanosheet Networks

Journal Article · Wed Jan 01 04:00:00 EST 2014 · Advanced Functional Materials

DOI:https://doi.org/10.1002/adfm.201401440· OSTI ID:1156737

Mahjouri-Samani, Masoud ^[1]; Gresback, Ryan G ^[1]; Tian, Mengkun ^[1]; Puretzky, Alexander A ^[1]; Rouleau, Christopher M ^[1]; Eres, Gyula ^[1]; Ivanov, Ilia N ^[1]; Xiao, Kai ^[1]; McGuire, Michael A ^[1]; Duscher, Gerd ^[2]; Geohegan, David B ^[1]

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1. ORNL
2. University of Tennessee, Knoxville (UTK)

Here we explore pulsed laser deposition (PLD), a well known and versatile synthesis method principally used for epitaxial oxide thin film growth, for the synthesis of functional metal chalcogenide (GaSe) nanosheet networks by stoichiometric transfer of laser vaporized material from bulk GaSe targets in Ar background gas. Uniform coverage of interconnected, crystalline, few-layer, photoresponsive GaSe nanosheets in both in-plane and out-of-plane orientations were achieved under different ablation plume conditions over ~1.5 cm2 areas. Plume propagation was characterized by in situ ICCD-imaging. High (1 Torr) Ar background gas pressures were found to be crucial for the stoichiometric growth of GaSe nanosheet networks. Individual 1-3 layer GaSe triangular nanosheets of ~ 200 nm domain size were formed within 30 laser pulses, coalescing to form nanosheet networks in as few as 100 laser pulses. The thickness of the deposited networks increased linearly with pulse number, adding layers in a two-dimensional (2D) growth mode while maintaining a surface roughness of 2 GaSe layers for increasing overall thickness. Field effect transistors using these interconnected crystalline GaSe networks showed p-type semiconducting characteristics with mobilities reaching as high as 0.1 cm2V-1s-1. Spectrally-resolved photoresponsivities and external quantum efficiencies ranged from 0.4 AW-1 and 100% at 700 nm, to 1.4 AW-1 and 600 % at 240 nm, respectively. Pulsed laser deposition under these conditions appears to provide a versatile and rapid approach to stoichiometrically transfer and deposit photoresponsive networks of 2D nanosheets with digital thickness control and substrate-scale uniformity for a variety of applications.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1156737
• Journal Information: Advanced Functional Materials, Journal Name: Advanced Functional Materials; ISSN 1616-301X
• Country of Publication: United States
• Language: English

Related Subjects

GaSe
PLD