Uniform Graphene Quantum Dots Patterned from Self-Assembled Silica Nanodots
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- 作者：Jinsup Lee ; Kyungho Kim ; Woon Ik Park ; Bo-Hyun Kim ; Jong Hyun Park ; Tae-Heon Kim ; Sungyool Bong ; Chul-Hong Kim ; GeeSung Chae ; Myungchul Jun ; Yongkee Hwang ; Yeon Sik Jung ; Seokwoo Jeon
- 刊名：Nano Letters
- 出版年：2012
- 出版时间：December 12, 2012
- 年：2012
- 卷：12
- 期：12
- 页码：6078-6083
- 全文大小：436K
- 年卷期：v.12,no.12(December 12, 2012)
- ISSN：1530-6992
文摘
Graphene dots precisely controlled in size are interesting in nanoelectronics due to their quantum optical and electrical properties. However, most graphene quantum dot (GQD) research so far has been performed based on flake-type graphene reduced from graphene oxides. Consequently, it is extremely difficult to isolate the size effect of GQDs from the measured optical properties. Here, we report the size-controlled fabrication of uniform GQDs using self-assembled block copolymer (BCP) as an etch mask on graphene films grown by chemical vapor deposition (CVD). Electron microscope images show that as-prepared GQDs are composed of mono- or bilayer graphene with diameters of 10 and 20 nm, corresponding to the size of BCP nanospheres. In the measured photoluminescence (PL) spectra, the emission peak of the GQDs on the SiO2 substrate is shown to be at 395 nm. The fabrication of GQDs was supported by the analysis of the Raman spectra and the observation of PL spectra after each fabrication step. Additionally, oxygen content in the GQDs is rationally controlled by additional air plasma treatment, which reveals the effect of oxygen content to the PL property.