Physical properties of amorphous Selenium superlattice structures for future X-ray detectors

Superlattices exhibit desirable electronic properties such as resonant tunneling. However, there is a high technology barrier for fabricating such structures, using methods such as molecular beam epitaxy (MBE). We fabricated multilayer structures of amorphous materials using the technologically simple method of rotational evaporation, and observed physical characteristics related to superlattice structures. The multi-layer structure was confirmed using Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS). The energy band structure of the superlattice was measured using Deep Level Transient Spectroscopy (DLTS). The results show minibands associated with superlattice structures, and oscillations in the transport properties. Using Current-Voltage (I-V) characterization, we could clearly observe such oscillations. From these results, quantum features associated with superlattices could be observed in multilayer amorphous Se fabricated using the rotational evaporation.