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Welcome at TFL!

(last update: 27.09.2023)

TFL has a multi-year experience in the field of deposition of thin films. TFL was the pioneer in Italy in research on laser fabrication and pulsed laser deposition of thin films (the first CO2 laser “made in Sicily” was fabricated here). Today, TFL owns a Nd:YAG pulsed laser deposition (PLD) system (also used as plasma-assisted PLD), and a CO2 laser-assisted thermal evaporation system which allows the growth of amorphous and device-quality crystalline films. The versatile set-up allows controlling many deposition parameters during the process (film thickness, temperature, gas pressure, etc.). TFL is provided of modern systems of electrical and optical thin film characterisation. Also, TFL researchers have access to the University scanning electronic microscope (SEM), transmission electronic microscope (TEM), and an equipped clean-room for microfabrications.
In TFL PLD is used to deposit films of CdS, HfO2, ITO, ZnO, the latter both n- and p-doped for application as blue light emitting diodes. CO2 laser system is currently used for the realisation of multidielectrics mirrors with tuneable reflectivity profile for application in laser resonators. (more info)

Research

  • Pulsed Laser deposition of oxide films
    The third harmonic (355 nm) of a pulsed Nd:YAG laser is used to deposit some transparent conductive oxides, such as ITO, AZO, or FTO on various substrates. The films are characterized in order to evaluate electrical and optical properties. (more info)
  • ZnO p-doping
    We investigate on the possibility to obtain p-type doped ZnO by pulsed laser deposition. ZnO target are syntherised with the desired amount of dopants, by a 25 MPa hydraulic press and a 1000°C oven. Element such as Li, Cu, and P are tested as possible p-type dopants. (more info)
  • Memristors
    Memristors are nonlinear, bias-dependent resistors, which can be used as memory elements. Resistive switching behaviour is observed in microscale memristors based on laser-ablated ZnO and VO2. Our results show that devices up to 300 x 300 mm² exhibit a memristive behaviour regardless of device size, and 100 x 100 mm² ZnO-based memristor have the best resistance off/on ratio. (more info)
  • White LEDs by frequency conversion of organic dyes
    High efficiency cool white light emitting diodes (LEDs) are obtained by generation of frequency down-conversion from a GaN/InGaN blue LED. Using photoluminescence of a perylene-based polymer dye we achieve a good substitute for conventional inorganic colour conversion. (more info)
  • Organic thin-film transistors
    Fabricated devices consist of FET structures (metal/anodic oxide/polymer/source-drain metallization) prepared on vacuum-deposited oxides (Ta2O5, Nb2O5). PEDOT is used as p-type semiconductor. (more info)
  • Fabrication of dielectric mirrors and filters
    Dielectric distributed Bragg reflectors (DBR) for nitride-based vertical cavity surface-emitting lasers (VCSEL) are deposited by CO2 laser-assisted thermal evaporation. We can design and fabricate DBR for each wavelength. (more info)

Teaching



University of Palermo  -  Department of Energy, Information engineering and Mathematical models (DEIM)
viale delle Scienze, Building 9  -  I-90128  Palermo (Italy)