Rectifying the output of vibrational piezoelectric energy harvester using quantum dots

TL;DR

This paper introduces a novel integrated piezoelectric energy harvester that uses a quantum dots layer to rectify electrical charges, reducing energy loss and eliminating the need for external rectification circuits.

Contribution

The study proposes a new device structure combining quantum dots with piezoelectric material to improve rectification and efficiency in energy harvesting.

Findings

Quantum dots can effectively rectify charges in piezoelectric harvesters.

The QDs layer reduces energy loss compared to traditional rectifiers.

The integrated device is more compact and consumes less power.

Abstract

Piezoelectric energy harvester scavenges mechanical vibrations and generates electricity. Researchers have strived to optimize the electromechanical structures and to design necessary external power management circuits, aiming to deliver high power and rectified outputs ready for serving as batteries. Complex deformation of the mechanical structure results in charges with opposite polarities appearing on same surface, leading to current loss in the attached metal electrode. External power management circuits such as rectifiers comprise diodes that consume power and have undesirable forward bias. To address the above issues, we devise a novel integrated piezoelectric energy harvesting device that is structured by stacking a layer of quantum dots (QDs) and a layer of piezoelectric material. We find that the QD can rectify electrical charges generated from the piezoelectric material because of its adaptable conductance to the electrochemical potentials of both sides of the QDs layer, so that electrical current causing energy loss on the same surface of the piezoelectric material can be minimized. The QDs layer has the potential to replace external rectification circuits providing a much more compact and less power-consumption solution.