Laboratory of physics of semiconductors and nano-structures
Gruppo di Lavoro
Giuseppe Zollo
The laboratory is mainly devoted to the study of the structural and the electronic properties of semiconductors and nano-sized materials, both from the experimental and the theoretical/computational point of view. Concerning the theoretical and computational physics activity, the laboratory owns a computational infrastructure with a total of more than 250 cores and four servers for high performing computing (HPC) (see Fig.1(a)). Structural characterization of materials and nano-structures is mainly performed by Transmission Electron Microscopy (TEM), optical microscopy and Reflection High Energy Electron Diffraction (RHEED). The laboratory owns two electronic microscopes, the first one operating in transmission at 160 kV [Fig. 1(b)], the other equipped with an high resolution reflection stage for RHEED measurements and shown in Fig. 1(c). The laboratory owns also the entire equipment needed to build and prepare samples for TEM, including the final ion milling stage [Fig. 1(d)].
Figure 1: Some of the main apparata owned by the laboratory
Concerning the electrical and the electronic characterization of materials, the laboratory is equipped with a set-up for measuring a variety of quantities such as the sheet resistance, the Hall voltage, the carrier density in semiconductors and thin films. The same experimental set-up has been equipped wth a liquid nitrogen cryostat to perform temperature controlled measurements of the activation energy of defects and traps [Fig. 1(e)]. With the same set-up, that is entirely controlled remotely, it is possible to perform Current Transient Spectroscopy (CTS) and Photo-Induced CTS (PICTS) measurements to study the behavior of traps and defect in semiconductors. Lastly the laboratory is equipped with a High Power Pulsed Laser system in conjunction with a controlled atmosphere system to perform experiments of laser induced modifications of the structural and the electronic properties of materials [see Fig. 1(f)].