Highly Tunable Charge Transport in Layer-by-Layer Assembled Graphene Transistors
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- 作者：Hyunmin Hwang ; Piljae Joo ; Moon Sung Kang ; Gukmoon Ahn ; Joong Tark Han ; Byeong-Su Kim ; Jeong Ho Cho
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：March 27, 2012
- 年：2012
- 卷：6
- 期：3
- 页码：2432-2440
- 全文大小：597K
- 年卷期：v.6,no.3(March 27, 2012)
- ISSN：1936-086X
文摘
We demonstrate a controlled, systematic method to tune the charge transport in graphene field-effect transistors based on alternating layer-by-layer assembly of positively and negatively charged graphene oxide followed by thermal reduction. Surprisingly, tuning the number of bilayers of thermally reduced graphene oxide multilayer films allowed achieving either ambipolar or unipolar (both n- and p-type) transport in graphene transistors. On the basis of X-ray photoemission spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry, and temperature-dependent charge transport measurements, we found that nitrogen atoms from the functional groups of positively charged graphene oxide are incorporated into the reduced graphene oxide films and substitute carbon atoms during the thermal reduction. This nitrogen-doping process occurs in different degrees for graphene multilayers with varying numbers of bilayers and thereby results in the interesting transition in the electrical behavior in graphene multilayer transistors. We believe that such a versatile method to control the charge transport in graphene multilayers will further promote their applications in solution-processable electronic devices based on graphene.