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9ALT'22
LM-I-8
LASER-MATTER INTERACTION
Ultrafast laser processing of photosensitive planar junctions in graphene and carbon nanotube field-effect transistors
1- National Research University of Electronic Technology, 1 Shokin square, Moscow, Zelenograd, Russia 2- P. N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninsky Prospect, Moscow, Russia 3- BioSense Institute, University of Novi Sad, 1 Dr Zorana Djindjica, Novi Sad, Serbia Main author email address: emmsowton@gmail.com
The ultrafast laser processing of low-dimensional materials is a new powerful tool for tailoring the electronic, optical and mechanical properties of matter via interaction with low energy photons. When the ultrashort laser pulse interacts with free electrons in the hexagonal carbon lattes the different dynamics of hot electronics can occur resulting in the different effect of atomic structure as well as chemical properties of materials. Even the ablation of carbon lattice can have different mechanism when irradiated with femtoseconds laser pulses. We have shown that depending on the accumulated fluence managed by number of picoseconds laser pulses the graphene ablation can happen by two different mechanisms [1]: thermo-acoustical layer detachment and photochemical oxidative etching. The physical mechanism behind these effect can lay in the integration of hot electrons and photons on different time scales. While pulses are separated in time for low frequencies the only higher energies can lead to braking the C-C bonds and detaching the carbon lattice resulting in "conventional" ablation. At a high repetition rate of low-intensity pulses with a period shorter than the decay time of optical photons, hot electrons are excited and the surrounding molecules are activated, which leads to photochemical processes, such as oxidation in the presence of oxygen molecules [2].
In this report we demonstrate the using of photochemical interaction of femtosecond laser pulses with the channel of field-effect transistors made of graphene or carbon nanotubes to produce planar junction sensitive to visible light. Pristine graphene and carbon nanotubes show a very weak response to visible light; while are activly studied for IR application.The fabrication of planar junctions in carbon nanomaterials is a promising way to increase the optical sensitivity of optoelectronic nanometer-scale devices in photonic connections, sensors, and photovoltaics [3, 4]. Utilizing a unique lithography approach based on direct femtosecond laser processing, a fast and easy technique for modification of graphene and single-walled carbon nanotube (SWCNT) optoelectronic properties through localized two-photon oxidation is developed. It results in a novel approach of quasi-metallic to semiconducting nanotube conversion so that metal/semiconductor planar junction is formed via local laser patterning. The fabricated planar junction in the field-effect transistors based on individual SWCNT drastically increases the photoresponse of such devices. The broadband photoresponsivity of the two-photon oxidized structures reaches the value of 2*107 A/W per single SWCNT at 1 V bias voltage and zero gate votage. The SWCNT-based transistors with induced metal/semiconductor planar junction can be applied to detect extremely small light intensities with high spatial resolution. We also had demonstrated that the pho-tocurrent generation in p-p+ junctions formed in single-layer graphene is related to the photothermoelectric effect. The photoresponsitivity of laser patterned single-layer graphene junctions is shown to be as high as 100 mA/W with noise equivalent power less than 6 kW/cm2. These results open a path to a low-cost maskless technology for fabrication of graphene-based optoelectronic devices with tunable properties for spectroscopy, signal processing, and sesning applications.
[1] I. Bobrinetskiy, A. Emelianov, A. Nasibulin, I. Komarov, N. Otero, P.M. Romero, Photophysical and photochemical effects in ultrafast laser patterning of CVD graphene, Journal of Physics D: Applied Physics, vol. 49(41), pp. 41LT01 (2016).
[2] J. Aumanen, A. Johansson, J. Koivistoinen, P. Myllyperkio, M. Pettersson, Patterning and tuning of electrical and optical properties of graphene by laser induced two-photon oxidation, Nanoscale, vol. 7, pp. 2851, (2015).
[3] A.V. Emelianov, D. Kireev, A. Offenhausser, N. Otero, P.M. Romero, I.I. Bobrinetskiy, Thermoelectrically Driven Photocurrent Generation in Femtosecond Laser Patterned Graphene Junctions, ACS Photonics, vol. 5(8), pp. 3107-3115, (2018)
[4] A.V. Emelianov, N.P. Nekrasov, M.V. Moskotin, G.E. Fedorov, N. Otero, P.M. Romero, V.K. Nevolin, B.I. Afinogenov, A.G.
Nasibulin, I.I. Bobrinetskiy, Individual SWCNT Transistor with Photosensitive Planar Junction Induced by Two-Photon Oxidation.
Adv. Electron. Mater., vol. 7, pp. 2000872(1-11), (2021).
A.V. Emelianov1,2, N.P. Nekrasov1, I.I. Bobrinetskiy1,3
