Long term retention in δ‐PVDF thin film prepared by rapid ice quenching technique

• Published in: Journal of applied polymer science 2023-04, Vol.140 (15), p.n/a
• Main Authors: Malik, Pinki, Gupta, Varun, Mishra, Hari Krishna, Kumar, Ajay, Mandal, Dipankar
• Format: Article
• Language: English
• Subjects: Capacitance; Curie temperature; Electric fields; Ferroelectric materials; Ferroelectricity; ice‐quenched; Materials science; memory window; Polymers; Polyvinylidene fluorides; PVDF; Quenching; retention; Thin films; δ‐PVDF
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.53714

Ferroelectric δ‐phase comprising polyvinylidene fluoride (δ‐PVDF) thin films are prepared via spin‐coating followed by high‐temperature annealing and rapid ice quenching, where, the requirement of a high electric field (~MV/m) is circumvented. Herein, ferroelectric responses, that is, “write,” “erase,” and “read” pulses on as prepared δ‐PVDF thin film, have been demonstrated through piezoresponse force microscopy (PFM). A metal‐ferroelectric‐insulator–semiconductor (MFIS) diode containing δ‐PVDF has shown a capacitance–voltage (C–V) hysteresis with a notable memory window of 7.5 V up to a temperature of 140°C, overcoming lower fatigue temperatures, limited by Curie transition in co‐polymer P(VDF‐TrFE). A very stable polarization state is reflected by a holding period of a capacitance state of 10 h, where only a 5% loss of its initial value is noticed. The excellent ferroelectric response and retention behavior of the δ‐PVDF thin film may open up new opportunities in the field of high‐endurance non‐volatile memories. In this work, we show that the thermal annealing followed by ice quenching technique can achieve electroactive δ‐phase in PVDF film. It indicates that the application of electric field for δ‐phase nucleation is possible to avoid which often leads to the electrical breakdown.