Ahmad N Abbas

US Patent:

20170322166, Nov 9, 2017

Filed:

May 5, 2017

Appl. No.:

15/587914

Inventors:

- Los Angeles CA, US
Ahmad Abbas - Los Angeles CA, US

International Classification:

G01N 27/12
G01N 33/00
C23C 14/58
C23C 14/18
C23C 14/04
C23C 14/30
H01J 37/305
B23K 20/00
B23K 101/38

Abstract:

The inventors experimentally demonstrated NOgas sensing performance of multilayer black phosphorous (BP) field effect transistors. The BP sensors were sensitive to NOconcentration 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 NO, 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 NOconcentrations suggests NOmolecules 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.