Atoms and molecules of simple gases

In this part we dwell on the properties of the simplest radicals and atoms in the adsorbed layer of oxide semiconductors as well as analyse the quantitative relationships between concentrations of these particles both in gaseous and liquid phases and on oxide surfaces (mostly for ZnO), and effect of former parameters on electrophysical parameters. Note that describing these properties we pursue only one principal objective, i. e. to prove the existence of a reliable physical and physical-chemical basis for a further development and application of semiconductor sensors in systems and processes which involve active particles emerging on the surface either as short-lived intermediate formations, or are emitted as free particles from the surface into the environment (heterogeno-homogeneous processes). 

As with donor particles, in order to resolve the posed problem it is initially necessary to prove experimentally a rigorous validity relationships derived in above domain of parameters (pressure and temperature) based on substantially wide number of experimental results. It is known that when preparing such experiments it is recommended to avoid various reefs which may provoke an experimentalist to take wrong assumptions for real, or to hide from a theorist, for example, simple functions in relationships analysed. Pioneering experiments conducted with acceptors involved such active particles as molecular oxygen which on the one hand possesses strong acceptor properties, and on the other is a fairly widespread and chemically sufficiently stable element. 

Based on results obtained we built [19] a sensitive oxygen analyzer which we have widely used in our further studies (see next chapter for details). 

It should be noted however that the method related to the measurements of equilibrium or stationary oxygen concentrations by means of sensors is not always applicable and convenient even in this particular case. Sometimes too much time is required to conduct these measure- 

It was first shown in study [37] that adsorption of N-atoms on films of zinc oxide reduces its conductivity to a certain stationary value which depends, as with oxygen atoms, both on the stationary concentration of particles in the volume adjacent to the sensor s film and on the temperature. 

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