US 10,648,959 B2 · Black phosphorus gas sensor

Abstract

The inventors experimentally demonstrated NO2 gas sensing performance of multilayer black phosphorous (BP) field effect transistors. The BP sensors were sensitive to NO2 concentration down to 5 ppb making them comparable in sensitivity to the best 2D material based sensors. Raman spectroscopy comparison revealed no apparent change in the spectra before and after exposure to NO2, which shows that thick BP flakes can maintain their relative stability after sensing. Moreover, the BP device sensing performance fitted well with the Langmuir Isotherm for molecules adsorbed on a surface, which confirms charge transfer as the dominant mechanism for sensing. The systematic increase in conductance with increasing NO2 concentrations suggests NO2 molecules withdraw electrons and dope BP flakes with holes. These results lay the ground work for BP to be applied to various sensing applications including chemical, gas, and bio-sensors.

Claims17

Dependent claims

A black phosphorus gas sensor having repeatable sensing performance, the sensor comprising:

a substrate;
a black phosphorus flake supported by the substrate, the black phosphorus flake having a thickness greater than 15 nanometers;
and
a plurality of electrical contacts supported by the substrate and coupled to the black phosphorus flake,
wherein the substrate, black phosphorus flake, and plurality of electrical contacts form a field effect transistor;
wherein the black phosphorus flake responds to a gas, resulting in the conduction of the field effect transistor based on the concentration of the gas;
and
wherein the plurality of electrical contacts includes respective Ti/Au contacts.

5 more elements

Dependencies are inferred from the claim text.

Black phosphorus gas sensor

Life of this patent

Black phosphorus gas sensor

Life of this patent

Abstract

Claims17