The thermal-to-electrical energy conversion in (Bi0.5Na0.5)0.94Ba0.06TiO3/graphene oxide heterogeneous structures

Abstract

In this work, a pyroelectric device based on (Bi0.5Na0.5)0.94Ba0.06TiO3/graphene oxide (BNT-BT/GO) heterogeneous structures is designed and fabricated for the first time. BNT-BT/GO is obtained by a controlled Langmuir-Blodgett (L-B) assembly method, and the device for thermal-to-electrical energy conversion is fabricated from the BNT-BT/GO heterogeneous structures via an etching process. The morphology, pyroelectric properties and the thermal-to-electrical energy conversion of BNT-BT/GO have been characterized and evaluated. Notably, the fabricated BNT-BT/GO device exhibits a giant electrocaloric effect, and the refrigeration temperature change is ~7.09 K at 110 °C. More importantly, the heterogeneous structure is proved to have remarkable thermal-to-electrical energy conversion properties, whose energy density is as high as 1.361 J cm−3 with temperatures varying between 30 and 120 °C. The results demonstrate that the ferroelectric heterogeneous structures are promising for waste-heat harvesting.