title: Two-dimensional CdS nanosheet-based TFT and LED nanodevices.
abstract: Semiconductor nanosheets have several unique applications in electronic and optoelectronic nanodevices. We have successfully synthesized single-crystalline n-type CdS nanosheets via a chemical vapor deposition (CVD) method in a Cd-enriched ambient. The as-synthesized nanosheets are typically 40-100 nm thick, 10-300 µm wide, and up to several millimeters long. Using the nanosheets, we fabricated for the first time (to our knowledge), nano thin-film transistors (nano-TFTs) based on individual CdS nanosheets. A typical unit of such nanosheet TFTs has a high on-off ratio (∼1.7 ×10(9)) and peak transconductance (∼14.1µS), which to our knowledge are the best values reported so far for semiconductor nano-TFTs. In addition, we fabricated n-CdS nanosheet/p(+)-Si heterojunction light emitting diodes (LEDs) with a top electrode structure. This structure, where the n-type electrode is directly above the junction, has the advantage of a large active region and injection current favorable for high-efficiency electroluminescence (EL) and lasing. Room-temperature spectra of the LEDs consist of only an intense CdS band-edge emission peak (∼507.7 nm) with a full width at half-maximum of about 14 nm.
authors.affiliation: State Key Lab for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ye
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Gao
authors.forename: Hu
authors.initials: H
authors.lastname: Meng
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Lun
authors.initials: L
authors.lastname: Dai
authors.forename: Guogang
authors.initials: G
authors.lastname: Qin