Giorgio Pettinari
CNR IFN
Giorgio Pettinari is a researcher at the Institute for Photonics and Nanotechnologies of the National Research Council of Italy. He got a Ph.D. in Materials Science from Sapienza University of Rome (Italy; 2008) and was an assistant researcher at the Radboud University of Nijmegen (The Netherlands; 2009-2011) and a Marie Curie Research Fellow at the University of Nottingham (UK; 2011-2013). His interests range from the experimental investigation of semiconductor nanostructures to micro- and nano-fabrication and investigation of photonic and plasmonic devices. He published >40 peer-reviewed papers, 2 invited book chapters, and given >20 oral contributions and seminars (7 invited).
Dilute nitrides (such as GaAsN, GaPN, and InGaAsN) are III-V semiconductors alloying small, yet macroscopic (≤ 5%) percentages of nitrogen atoms. One of the most striking property of this class of materials is the... [ view full abstract ]
Dilute nitrides (such as GaAsN, GaPN, and InGaAsN) are III-V semiconductors alloying small, yet macroscopic (≤ 5%) percentages of nitrogen atoms. One of the most striking property of this class of materials is the possibility of tuning post-growth the alloy properties, as for example the band gap energy, by a controlled incorporation of hydrogen atoms. The formation of N-H complexes, indeed, neutralizes all the effects N has on the host matrix, among which the strong narrowing of band gap energy [1]. In the past years, we have demonstrated the possibility to get an in-plane band gap engineering in dilute nitrides by making use of lithographic [2] or laser-assisted [3,4] approaches to spatially control, respectively, the incorporation or removal of hydrogen atoms.
Here, we extend our studies to plasmonic structures in order to use their inherent ability to localize light at length scale well below the diffraction limit, with the aim of controlling the H removal in dilute nitrides at the nanometer scale and realize spatially controlled quantum emitters. In particular, we present a comprehensive investigation of the structural and optical properties of single bowtie-shaped plasmonic nanoapertures (NAs) in Al thin film. Different bowtie NAs have been realized by lithographic approach and investigated by scanning probe microscopy (SEM, AFM; Figs. 1a,b), FEM simulations (Figs. 1c,d), and resonant scattering spectroscopy (Fig. 1e). The condition to get the maximum field enhancement below the metal/semiconductor interface, namely at the dilute nitride quantum well (QW) position, has been identified. NAs have then been successfully employed to perform a spatially selective hydrogen removal in a fully hydrogenated GaAsN QW (Fig. 1f). The hydrogen removal results to be up to five times more efficient through the bowtie NAs than on the plain sample surface; thus demonstrating the potentiality of the plasmon-induced in-plane band gap engineering for future realization of site-controlled single-photon emitters.
[1] G. Pettinari et al., JAP 115, 012011 (2014); Photonics 5, 10 (2018).
[2] R. Trotta et al., Adv. Mater. 23, 2706 (2011).
[3] N. Balakrishnan et al., PRB 86, 155307 (2012).
[4] F. Biccari et al., Adv. Mater. 30, 1705450 (2018).
Photonic & plasmonic nanomaterials , Quantum dots and colour centres
