Chemistry Reference
In-Depth Information
1.7 EXPERIMENTAL TECHNIQUES
Electrochemical techniques generally involve the measurement of the electrical
signal of the semiconductor/electrolyte interface since the elemental step in an elec-
trochemical reaction is charge transfer across the charged layers at the interface. In
these techniques, the electrode surface is typically perturbed by a signal of potential,
current, or light, and the corresponding potential, current, or light, along with the phys-
ical and chemical changes that take place on the surface, is measured. The physical and
chemical nature of the interface layers and kinetics of the electrode reactions can then
be analyzed. The theories and methodologies employed in electrochemical techniques
are well documented.
44,932,962-964
The properties of silicon electrodes has been investigated using a wide range of
experimental techniques. Specific examples are the determination of:
Steady-state or dynamic potential and current relationships to provide infor-
mation on the energetic dependence of electrode reaction rate
2,21,34,271,939
Current or potential versus time to provide information concerning stability of
reactions and transition or transformation of surface condition
74,77,286,291,860,874
Capacitance-potential relationship to reveal information on the energetic
position of semiconductor bands and surface states, especially the flatband
potential
61,93,475,479,716,841,942
Impedance
frequency relationship to yield information on the resistive and
capacitive elements of the current path
9,139,486,951
Current on rotating electrode to give information regarding mass transport
in electrolyte
14,34,939
-
and on rotating ring-disk electrode for reaction
intermediates
21,695
Short-circuit current of a
p-n
junction to discriminate between a conduction
and a valence band process
34,969
Photocurrent to provide information on quantum efficiency and types of
carriers
11,73,74,873
Impedance under illumination to generate information on recombination
93,808,932
processes
Photocurrent with subband light to provide information on surface states
400,935
Optoelectric impedance (photopotential or current response to modulated illu-
mination) or electro-optic impedance (photoresponse to potential modulation)
for information on the contribution of minority, majority, and injected carriers
in recombination and multiplication
626,932
Microwave conductivity for instantaneous minority concentration and flat-
band potential
597,616
Optical second-harmonic generation by pulsed laser for structural information
on interface
606
Defletometric technique for electrolyte concentration gradien near the solid
electrode surface
855,862
Bending beam method for stress of oxide film on the surface
1058
Micropatterned samples for determination of carrier distribution and lateral
mobility across the electrode or near the surface
585,587
