"Microwave flexible transistors on cellulose nanofibrillated fiber substrates"
Appl. Phys. Lett. 106, 262101 (2015); http://dx.doi.org/10.1063/1.4921077
Jung-Hun Seo (Department of Electrical and Computer Engineering, University of Wisconsin Madison),
Tzu-Hsuan Chang (Department of Electrical and Computer Engineering, University of Wisconsin Madison),
Jaeseong Lee (Department of Electrical and Computer Engineering, University of Wisconsin Madison),
Ronald Sabo (USDA Forest Products Laboratory),
Weidong Zhou (Department of Electrical Engineering, University of Texas),
Zhiyong Cai (USDA Forest Products Laboratory),
Shaoqin Gong (Department of Biomedical Engineering, Wisconsin Institute for Discovery),
Zhenqiang Ma (Department of Electrical and Computer Engineering, University of Wisconsin Madison).
In this paper, we demonstrate microwave flexible thin-film transistors (TFTs) on biodegradable substrates towards potential green portable devices. The combination of cellulose nanofibrillated fiber (CNF) substrate, which is a biobased and biodegradable platform, with transferrable single crystalline Si nanomembrane (Si NM), enables the realization of truly biodegradable, flexible, and high performance devices. Double-gate flexible Si NM TFTs built on a CNF substrate have shown an electron mobility of 160 cm2/V·s and f T and f max of 4.9 GHz and 10.6 GHz, respectively. This demonstration proves the microwave frequency capability and, considering today's wide spread use of wireless devices, thus indicates the much wider utility of CNF substrates than that has been demonstrated before. The demonstration may also pave the way toward portable green devices that would generate less persistent waste and save more valuable resources.