Piezoelectric and Pyroelectric Effects Induced in Silicon Schottky Diodes

events hall

Sunday, Jul 9th , 2023 at 14:30

David Wang Auditorium, 3rd floor, Dalia Maydan Bldg.

Ms. Aya Mohammd Mrar – MSc candidate

Department of Materials Science and Engineering
Technion – Israel Institute of Technology, Haifa

Piezoelectricity and pyroelectricity refer to the change of electrical polarization across a material due to mechanical and thermal stimuli, correspondingly. These effects are exhibited in materials crystalizing in non-centrosymmetric crystal structures. Nevertheless, the material symmetry of centrosymmetric materials can be lowered by external stimuli. The electric field can break the inversion symmetry and induces polarization, which results in emergent piezoelectric and pyroelectric effects. This electric field can arise from either an external source or be built-in by the system itself. The latter case is commonly observed at the interfaces of semiconductor heterostructures. One example is PN or Schottky junctions based on Si which is a centrosymmetric material.
In this work, silicon Schottky junctions were fabricated with the motivation of understanding their electromechanical and pyroelectric properties. We studied the converse piezoelectric effect in the Schottky junction by applying an alternating and direct bias to the junction and measuring the resulting surface displacement via resonance-enhanced piezo response force microscopy. Moreover, we studied the signature of the pyroelectric effect by electrical characterization of the Schottky junctions while changing the temperature.
Considering the role of silicon in microelectronics, the integration of silicon-based electromechanical or pyroelectric devices could have huge advantages in sensing and actuating applications.

Aya completed her Bachelor of Science in Materials Engineering from Azrieli College of Engineering, Jerusalem, in 2020.
During her undergraduate studies, she participated in research on the development of
microelectronic devices for integration in biosensors in Prof. Shlomo Yitzchaik’s laboratory at the
Department of Chemistry at the Hebrew University in Jerusalem.
Her MSc research topic in Yonatan Calahora’s group is “Piezoelectric and Pyroelectric Effects Induced in Silicon Schottky Diodes”.