22 / 24
Smart Materials Congress 2019
Nano Research and Applications
ISSN: 2471-9838
Page 50
August 01-02, 2019
Dublin, Ireland
Smart Materials and
Structures
8
th
International Conference on
Nano Res Appl 2019, Volume 05
Photosensitive inverters and light-to-frequency conversion
circuits based on transistion metal dichalcogenides field
effect transistors
Sung Hun Jin
Incheon National University, South Korea
R
ecently transisiton metal dichalcogenides (TMDCs)
such as MoS
2
, WSe
2
, MoTe
2
, WS
2
and others haved
been emerged and actively researched as one of next
generation semiconductors for extending Moore’s law.
Among a variety of novel properties for TMDCs, one of
interesting properties is to modulate energy bandgap
(Eg) in variation of number of layers. In this study, for
the improvement of noise immunity for IoT sensor
systems, photo sensitive inverters and their light-to-
frequency conversion circuts (LFCs) are proposed and
experimentally demonstrated by using the platform
comprised of an enhancement MoS
2
driver with light-
shield layers (LSLs) (or GaN FET drivers) and MoS
2
depletion load. Moreover, for energy efficient circuits,
complementary photo- sensitive inverters based on
p-type MoTe
2
and n-type MoS
2
FETs are demonstrated.
For the better understanding on performance of LFCs,
we systematically studied basic design rules on LFCs via
experimentally measured voltage transfer characteristics
of photo-sensitive inverters and their spice simulation
with their extracted model parameters based on RPI
model (i.e., SILVACO, Smart-spice; level 36). The
simulation results illustrate that key parameters of ring
osciallators (ROs) such as oscillation frequency (fosc)
and peak-to peak voltage (Vp-p) can be systematically
controlled by inverter parameters such as noise margin,
voltage gains associated with electrical parameters (i.e.,
Vth, SS, current on/off ratio, field effect mobility, etc).
In the present study, experimental implementation of
photosensitive inverters based on MoS
2
, MoTe
2
, and GaN
FETs, etc. and their systematic validation on performance
via spice simulation yield insightful design rules required
for reliable operation of LFCs, potentially contributing to
emerging IoT security systems.
shjin@inu.ac.kr