title: p-Type polymer-hybridized high-performance piezoelectric nanogenerators.
abstract: Enhancing the output power of a nanogenerator is essential in applications as a sustainable power source for wireless sensors and microelectronics. We report here a novel approach that greatly enhances piezoelectric power generation by introducing a p-type polymer layer on a piezoelectric semiconducting thin film. Holes at the film surface greatly reduce the piezoelectric potential screening effect caused by free electrons in a piezoelectric semiconducting material. Furthermore, additional carriers from a conducting polymer and a shift in the Fermi level help in increasing the power output. Poly(3-hexylthiophene) (P3HT) was used as a p-type polymer on piezoelectric semiconducting zinc oxide (ZnO) thin film, and phenyl-C(61)-butyric acid methyl ester (PCBM) was added to P3HT to improve carrier transport. The ZnO/P3HT:PCBM-assembled piezoelectric power generator demonstrated 18-fold enhancement in the output voltage and tripled the current, relative to a power generator with ZnO only at a strain of 0.068%. The overall output power density exceeded 0.88 W/cm(3), and the average power conversion efficiency was up to 18%. This high power generation enabled red, green, and blue light-emitting diodes to turn on after only tens of times bending the generator. This approach offers a breakthrough in realizing a high-performance flexible piezoelectric energy harvester for self-powered electronics.
authors.affiliation: School of Advanced Materials Science and Engineering, Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University (SKKU), Suwon 440-746, Republic of Korea.
authors.forename: Keun Young
authors.initials: KY
authors.lastname: Lee
authors.forename: Brijesh
authors.initials: B
authors.lastname: Kumar
authors.forename: Ju-Seok
authors.initials: JS
authors.lastname: Seo
authors.forename: Kwon-Ho
authors.initials: KH
authors.lastname: Kim
authors.forename: Jung Inn
authors.initials: JI
authors.lastname: Sohn
authors.forename: Seung Nam
authors.initials: SN
authors.lastname: Cha
authors.forename: Dukhyun
authors.initials: D
authors.lastname: Choi
authors.forename: Zhong Lin
authors.initials: ZL
authors.lastname: Wang
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Kim
mesh_terms: D011211:Electric Power Supplies; D037741:Fullerenes / Q000737:chemistry; D008567:Membranes, Artificial; D036103:Nanotechnology / Q000295:instrumentation*; D016062:Porosity; D012666:Semiconductors; D013499:Surface Properties; D013876:Thiophenes / Q000737:chemistry*; D013997:Time Factors; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: C539575:(6,6)-phenyl C61-butyric acid methyl ester; D037741:Fullerenes; D008567:Membranes, Artificial; D013876:Thiophenes; C507295:poly(3-hexylthiophene); D015034:Zinc Oxide