US-12618885-B2 - Sensor device capable of measuring electric field strength of an external electric field and method for measuring external electric field

US12618885B2US 12618885 B2US12618885 B2US 12618885B2US-12618885-B2

Abstract

A sensor device capable of measuring electric field strength of an external electric field includes a first dielectric layer, a first atomic layer material film disposed on the first dielectric layer and including one or more atomic layers formed of a first material, a channel layer disposed on the first atomic layer material film, including a channel region, and including one or more atomic layers of graphene, a second atomic layer material film disposed on the channel layer and including one or more atomic layers formed of a second material, and a first electrode and second electrode disposed on the channel layer across the channel region in a manner facing each other, wherein the second atomic layer material film includes a first side and a second side, the first side being disposed on the channel layer and the portion of the second side opposite from the channel region being exposed to the outside, or a second dielectric layer being disposed on the second side and the portion on the side opposite from the channel region of the side of the second dielectric layer opposite from the second atomic layer material film being exposed to the outside.

Inventors

Afsal KNAREEKUNNAN
Hiroshi Mizuta
Manoharan MURUGANATHAN
Takeshi Kudo
Takeshi Maruyama

Assignees

OTOWA ELECTRIC CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20220905
Priority Date: 20210908

Claims (7)

1 . A sensor device capable of measuring electric field strength of an external electric field, and the sensor device comprises: a first dielectric layer; a first atomic layer material film disposed on the first dielectric layer and including one or more atomic layers formed of a first material; a channel layer disposed on the first atomic layer material film, including a channel region, and including one or more atomic layers of graphene; a second atomic layer material film disposed on the channel layer and including one or more atomic layers formed of a second material; and a first electrode and second electrode disposed on the channel layer across the channel region in a manner facing each other, wherein the second atomic layer material film includes a first side and a second side, the first side being disposed on the channel layer and a second dielectric layer being disposed above the second side and the portion on the side opposite from the channel region of the side of the second dielectric layer opposite from the second atomic layer material film being exposed to the outside.
2 . The sensor device according to claim 1 , wherein the first atomic layer material film includes 1 to 120 atomic layers formed of the first material.
3 . The sensor device according to claim 1 , wherein the second atomic layer material film includes 1 to 100 atomic layers formed of the second material.
4 . The sensor device according to claim 1 , wherein the first material or the second material is hexagonal boron nitride, molybdenum disulfide or tungsten disulfide.
5 . The sensor device according to claim 1 , wherein the channel layer includes 1 to 10 layers of graphene.
6 . A method for measuring an external electric field using a sensor device capable of measuring electric field strength of an external electric field, and the sensor device comprises: a first dielectric layer; a first atomic layer material film disposed on the first dielectric layer and including one or more atomic layers formed of a first material; a channel layer disposed on the first atomic layer material film, including a channel region, and including one or more atomic layers of graphene; a second atomic layer material film disposed on the channel layer and including one or more atomic layers formed of a second material; and a first electrode and second electrode disposed on the channel layer across the channel region in a manner facing each other, wherein the second atomic layer material film includes a first side and a second side, the first side being disposed on the channel layer and a second dielectric layer being disposed above the second side and the portion on the side opposite from the channel region of the side of the second dielectric layer opposite from the second atomic layer material film being exposed to the outside, the method comprising: measuring a current value flowing between the first electrode and second electrode while the external electric field is being applied to the sensor device; and determining electric field strength of the external electric field based on the current value.
7 . The method according to claim 6 , wherein the electric field strength is measured for an external electric field input from the side of the second dielectric layer opposite from the second atomic layer material film, or output from the side of the second dielectric layer opposite from the second atomic layer material film.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a National Phase under 35 U.S.C. 371 of PCT/JP2022/033318, filed on Sep. 5, 2022, and which designated the U.S., which claims priority to Japanese Patent Application No. 2021-146438, filed on Sep. 8, 2021. The contents of each are wholly incorporated herein by reference. FIELD The present disclosure relates to a sensor device capable of measuring electric field strength of an external electric field and a method for measuring an external electric field. BACKGROUND Sensor devices have been used for measurement of electric field strength in air. Measurement of electric field strength in air allows monitoring of developing and approaching thunderclouds (see PTL 1, for example). Sensor devices are also used to measure electric field strength in indoor atmospheres. Measurement of electric field strength allows monitoring of the condition of indoor static electricity to help prevent accidents caused by static electricity. Sensor devices used to measure electric field strength include mechanical sensor devices and semiconductor sensor devices. Mechanical sensor devices have relatively large dimensions and heavy weights (PTL 1, for example). Semiconductor sensor devices have relatively smaller dimensions and lighter weights (NPL 1, for example). A mechanical sensor device has electrodes with charge induced by application of an external electric field, a rotating plate having an opening that allows the electrodes to be exposed to the outside, and a driving unit that drives rotation of the rotating plate. In such a mechanical sensor device, rotation of the rotating plate causes the electrode to be exposed to the outside while repeatedly covering it by the rotating plate, thereby intermittently applying an electrostatic field to the electrode so that the electric field strength of the external electric field is measured as an AC signal generated in the electrode. A semiconductor sensor device has a transistor disposed on a substrate. The electric field strength of an external electric field applied to the substrate is measured as the amount of the current flowing between the source electrode and drain electrode when the transistor is in the ON state. CITATION LIST Patent Literature [PTL 1]Japanese Unexamined Patent Publication No. 2020-46213 Non Patent Literature NPL 1 Wang et al., High-performance graphene-based electrostatic field sensor, IEEE ELECTRON DEVICE LETTERS, Vol 38, No. 8, August 2017 SUMMARY Technical Problem Because of their large dimensions and heavy weights, mechanical sensor devices such as described above cannot be fitted into narrow spaces. Semiconductor sensor devices, having smaller dimensions and lighter weights, can be fitted into narrow spaces, but have the problem of having a high lower limit for the field strength that can be measured. Proposed herein is a sensor device that has small dimensions while also being capable of measuring low field strengths. Solution to Problem One embodiment of the sensor device disclosed herein is a sensor device capable of measuring the electric field strength of an external electric field, the sensor device having a first dielectric layer, a first atomic layer material film disposed on the first dielectric layer and having one or more atomic layers formed of a first material, a channel layer disposed on the first atomic layer material film, having a channel region, and having one or more atomic layers of graphene, a second atomic layer material film disposed on the channel layer and having one or more atomic layers formed of a second material, and a first electrode and second electrode disposed on the channel layer across the channel region in a manner facing each other, wherein the second atomic layer material film has a first side and a second side, the first side being disposed on the channel layer and the portion of the second side opposite from the channel region being exposed to the outside, or a second dielectric layer being disposed on the second side and the portion on the side opposite from the channel region of the side of the second dielectric layer opposite from the second atomic layer material film being exposed to the outside, or the second dielectric layer being disposed on the second side. According to one embodiment of the method for measuring an external electric field disclosed herein, the sensor device described above is used for measurement of an external electric field. The method is characterized by measuring the current value flowing between the first electrode and second electrode while the external electric field is applied to the sensor device, and determining the electric field strength of the external electric field based on the current value. Advantageous Effects The sensor device disclosed herein has small dimensions and allows measurement of small electric field strengths. The method for measuring an external electric field disclosed herein allows measurement of small e