Atomic layer deposited high-k dielectric on graphene by functionalization through atmospheric plasma treatment

Abstract

Atomic layer-deposited (ALD) dielectric films on graphene usually show noncontinuous and rough morphology owing to the inert surface of graphene. Here, we demonstrate the deposition of thin and uniform ALD ZrO films with no seed layer on chemical vapor-deposited graphene functionalized by atmospheric oxygen plasma treatment. Transmission electron microscopy showed that the ALD ZrO films were highly crystalline, despite a low ALD temperature of 150 °C. The ALD ZrO film served as an effective passivation layer for graphene, which was shown by negative shifts in the Dirac voltage and the enhanced air stability of graphene field-effect transistors after ALD of ZrO. The ALD ZrO film on the functionalized graphene may find use in flexible graphene electronics and biosensors owing to its low process temperature and its capacity to improve device performance and stability.

The effect of plasma treated carbon felt on the performance of aqueous quinone‐based redox flow batteries

“…To facilitate electron transfer by increasing catalytic activity and redox reactivity, the attachment of functional groups onto CFs can be one of solutions. Plasma treatment is a popular method to attach the proper functional groups to CFs uniformly 16,17 . Besides that, this plasma treatment is clean, solvent‐free, time saving, and environmentally friendly method 32‐34 .…”

“…Plasma treatment is a popular method to attach the proper functional groups to CFs uniformly. 16,17 Besides that, this plasma treatment is clean, solvent-free, time saving, and environmentally friendly method. [32][33][34] Of them, N 2 and O 2 plasmas are mostly famous and enable the proper surface modification of CFs.…”

“…5,16 Furthermore, oxygen and nitrogen (O and N)-doped carbon nanotubes were also challenged to form hydrophilic surface and to enable faster charge transfer on CF surface. [17][18][19][20] Yuqing et al reported the effect of O and N co-doped CF on the performance of vanadium redox flow battery (VRFB), and this VRFB could be stably operated until 30 cycles at 50 mAÁcm À2 . 21 Lydia group also did similar reasearch to Yuqing group.…”

“…To activate the electron transfer rate of TironA and alleviate the degradation in the performance of QRFB, N and O functional groups can be effective. 17,21 O functional groups, such as phenolic (C─O) and carboxyl (C═O) groups, which are formed via O 2 plasma treatment, act as active sites in electrode. Since the groups increase the hydrophilicity of CF surface, the redox reactivity of active materials also increases.…”

“…In spite of that, the electron transfer rate of TironA is still low, and the performance of QRFB using TironA, especially the voltage and energy efficiencies (VE and EE). To activate the electron transfer rate of TironA and alleviate the degradation in the performance of QRFB, N and O functional groups can be effective 17,21 …”