US 11,953,444 B2
Zero-power detecting sensor of chemical substance and sensing method
Chulho Lee, Seoul (KR); and Haeli Park, Seoul (KR)
Assigned to Korea University Research and Business Foundation, Seoul (KR)
Filed by Korea University Research and Business Foundation, Seoul (KR)
Filed on Mar. 11, 2019, as Appl. No. 16/298,012.
Claims priority of application No. 10-2018-0014042 (KR), filed on Feb. 5, 2018.
Prior Publication US 2019/0242827 A1, Aug. 8, 2019
Int. Cl. G01R 19/00 (2006.01); G01N 21/77 (2006.01); G01N 31/10 (2006.01); G01N 33/00 (2006.01); H01L 31/0336 (2006.01); H01L 31/109 (2006.01)
CPC G01N 21/77 (2013.01) [G01N 31/10 (2013.01); H01L 31/0336 (2013.01); H01L 31/109 (2013.01); G01N 2021/7753 (2013.01); G01N 33/0037 (2013.01); G01N 33/005 (2013.01); G01N 33/0054 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of determining an electronic property of a chemical substance without power, the method comprising:
flowing an air comprising the chemical substance to a detecting sensor comprising a bottom electrode, a light absorbing layer comprising n-Si directly disposed on the bottom electrode, an insulating layer directly disposed on a first portion of the light absorbing layer, a top electrode directly disposed on the insulating layer, and a graphene layer directly disposed on a second portion of the light absorbing layer to form a heterojunction therebetween and the graphene layer extending such that it is connected to the top electrode, while irradiating a light to the detecting sensor;
measuring a photocurrent generated by a photoreaction in the heterojunction between the graphene layer and the light absorbing layer comprising n-Si in response to the irradiating of the light absorbing layer in the air comprising the chemical substance without applying a driving voltage to the heterojunction;
measuring a control photocurrent generated from the light absorbing layer in a control air not comprising the chemical substance while irradiating the light to the detecting sensor;
and determining the electronic property of the chemical substance as electron-giving when the photocurrent decreases or as electron-receiving when the photocurrent increases compared to the control photocurrent measured when the control air not comprising the chemical substance flows to the detecting sensor, thereby detecting a presence of the chemical substance according to a change in the photocurrent,
wherein the graphene layer is prepared by a chemical vapor deposition and is not a reduced graphene oxide layer and
wherein the photocurrent generated with 5 ppm of NO2 is at least 1 μA.