Engineering of efficiency limiting free carriers and an interfacial energy barrier for an enhancing piezoelectric generation

• Published in: Energy & environmental science 2013-01, Vol.6 (1), p.97-104
• Main Authors: Sohn, Jung Inn, Cha, Seung Nam, Song, Byong Gwon, Lee, Sanghyo, Kim, Seong Min, Ku, JiYeon, Kim, Hyun Jin, Park, Young Jun, Choi, Byoung Lyong, Wang, Zhong Lin, Kim, Jong Min, Kim, Kinam
• Format: Article
• Language: English
• Subjects: Carrier density; Density; Electronics; Energy management; Harvesting; Nanostructure; Piezoelectricity; Zinc oxide
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/c2ee23404a

The energy harvesting efficiency is of tremendous importance for the realization of a high output-power nanogenerator serving as the basis for self-powered electronics. Here we report that the device performance of a sound-driven piezoelectric energy nanogenerator (SPENG) is remarkably improved by controlling both the carrier density and the interfacial energy in a semiconducting ZnO nanowire (NW), thereby achieving its intrinsic efficiency limits. A SPENG with carrier-controlled ZnO NWs exhibits excellent energy harvesting characteristics with an average power density of 0.9 mW cm super(-3), as well as a near 50 fold increase in both output voltage and current compared to those of a conventional ZnO NW. In addition, we demonstrate for the first time that an optimized SPENG is large enough and very suitable to drive electrophoretic ink displays based on voltage-drive systems. This fundamental progress makes it possible to fabricate high performance nanogenerators for viable industrial applications in portable/wearable personal electronics such as electronic papers and smart identity cards.