Giant Change in Electrical Resistivity Induced by Moderate Pressure in Pt(bqd)2 – First Candidate Material for an Organic Piezoelectronic Transistor (OPET)

The piezoelectronic transistor (PET) has been proposed to overcome the voltage and clock speed limitations of conventional field-effect transistors (FET). In a PET, voltage is transduced to stress, which leads to an insulator-metal transition in a piezo-resistive (PR) element. Although the simulated switching speeds are promising, the viable candidates proposed so far for the PR layer are rare earth compounds that require several GPa of pressure (P) to metalize, necessitating breakthroughs in transduction mechanism scaling and processing. Here, a PR candidate that metalizes in the 0–300 MPa range – the transition metal complex platinum benzoquinonedioximato (Pt(bqd)₂) is demonstrated. Such electrical sensitivity to the application of P arises when the material is grown as a thin film with the preferred needle orientation perpendicular to the substrate. As evidence, a combination of hydrostatic and uniaxial pressure studies is provided. The former studies are produced on the compressed powder pellet in a specially developed piston-cylinder cell (P-C cell) under variable temperatures (T) and P. The latter is via thin film deposition and uniaxial resistivity (ρ) measurements and these revealed the high potential of this material for the PET concept.