PMID- 21386504
OWN - NLM
STAT- MEDLINE
DCOM- 20110817
LR  - 20110309
IS  - 1361-648X (Electronic)
IS  - 0953-8984 (Linking)
VI  - 22
IP  - 33
DP  - 2010 Aug 25
TI  - Intrinsic doping and gate hysteresis in graphene field effect devices fabricated 
      on SiO2 substrates.
PG  - 334214
LID - 10.1088/0953-8984/22/33/334214 [doi]
AB  - We have studied the intrinsic doping level and gate hysteresis of graphene-based 
      field effect transistors (FETs) fabricated over Si/SiO(2) substrates. It was 
      found that the high p-doping level of graphene in some as-prepared devices can be 
      reversed by vacuum degassing at room temperature or above depending on the degree 
      of hydrophobicity and/or hydration of the underlying SiO(2) substrate. Charge 
      neutrality point (CNP) hysteresis, consisting of the shift of the charge 
      neutrality point (or Dirac peak) upon reversal of the gate voltage sweep 
      direction, was also greatly reduced upon vacuum degassing. However, another type 
      of hysteresis, consisting of the change in the transconductance upon reversal of 
      the gate voltage sweep direction, persists even after long-term vacuum annealing 
      at 200  degrees C, when SiO(2) surface-bound water is expected to be desorbed. We propose 
      a mechanism for this transconductance hysteresis that involves water-related 
      defects, formed during the hydration of the near-surface silanol groups in the 
      bulk SiO(2), that can act as electron traps.
FAU - Joshi, P
AU  - Joshi P
AD  - Department of Electrical Engineering, The Pennsylvania State University, 
      University Park, PA 16802, USA.
FAU - Romero, H E
AU  - Romero HE
FAU - Neal, A T
AU  - Neal AT
FAU - Toutam, V K
AU  - Toutam VK
FAU - Tadigadapa, S A
AU  - Tadigadapa SA
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20100804
PL  - England
TA  - J Phys Condens Matter
JT  - Journal of physics. Condensed matter : an Institute of Physics journal
JID - 101165248
RN  - 7631-86-9 (Silicon Dioxide)
SB  - IM
MH  - Equipment Design
MH  - Equipment Failure Analysis
MH  - Materials Testing
MH  - Nanostructures/*chemistry/*ultrastructure
MH  - Nanotechnology/*instrumentation
MH  - Particle Size
MH  - Silicon Dioxide/*chemistry
MH  - *Transistors, Electronic
EDAT- 2011/03/10 06:00
MHDA- 2011/08/19 06:00
CRDT- 2011/03/10 06:00
PHST- 2011/03/10 06:00 [entrez]
PHST- 2011/03/10 06:00 [pubmed]
PHST- 2011/08/19 06:00 [medline]
AID - S0953-8984(10)44083-7 [pii]
AID - 10.1088/0953-8984/22/33/334214 [doi]
PST - ppublish
SO  - J Phys Condens Matter. 2010 Aug 25;22(33):334214. doi: 
      10.1088/0953-8984/22/33/334214. Epub 2010 Aug 4.