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We experimentally demonstrate the heterogeneous integration of ferroelectric hafnium zirconium oxide (HZO) with a silicon photonic microring resonator and demonstrate two non-volatile states for data storage by switching the polarization of HZO. Capped by transparent conducting titanium doped indium oxide (ITiO), the device functions as a metal insulator semiconductor (MIS) capacitor and utilizes the refractive index modulation via carrier (hole) accumulation and the effect of trapped charges at the ferroelectric–silicon interface to create the non-volatile binary switching states. In contrast to electronic devices where trapped charges at the silicon–ferroelectric interface reduce the memory window, in our ferrophotonic device, trapped charges amplify the refractive index difference in the binary states due to effective screening of the silicon in inversion. By switching the applied bias from negative to positive, the optical power transmitted through the ring switches with 3.5 dB output power difference between the non-volatile set and reset states and 40 pJ switching energy at ±8 V. Preliminary results suggest a path toward achieving sub-1 V non-volatile ferrophotonic switching.
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Thermoelectric transport at F4TCNQ–silicon interface
Hybrid organic-inorganic materials are among the latest class of materials proposed for thermoelectric applications. The organic-inorganic interface is critical in determining the effective transport properties of the hybrid material. We study the thermoelectric properties of the tetrafluoro-tetracyanoquinodimethane (F4TCNQ)–silicon interface. Transfer of electrons from silicon to F4TCNQ results in holes trapped within the screening length of the interface that can move parallel to the interface. We measure the response of these trapped charges to applied temperature differential and compare the thermoelectric transport properties of the silicon with and without F4TCNQ. The results confirm the presence of interface charges and demonstrate an enhanced interface thermoelectric power factor. These outcomes of this study could be used in designing 3D hybrid structures with closely packed interfaces to replicate a bulk thermoelectric material.
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- Award ID(s):
- 1400246
- PAR ID:
- 10594727
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- APL Materials
- Volume:
- 7
- Issue:
- 2
- ISSN:
- 2166-532X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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