introduction and its type

1. INTRODUCTION
TO
SEMICONDUCTOR
ELECTROCHEMISTRY

2. WHAT IS
SEMICONDUCTOR
ELECTROCHEMISTRY
Semiconductor electrochemistry is a field that studies the
electrochemical properties of semiconductors and their
applications in various fields such as energy conversion,
environmental remediation, and sensing. It involves the
study of the interaction between light, electrons, and
chemical reactions at the surface of semiconductors.

3. BASIC PRINCIPLE
Semiconductors are materials that have electrical
conductivity between that of metals and insulators. They
have a band gap, which is the energy difference between
the valence band and the conduction band. When light is
absorbed by a semiconductor, electrons are excited from
the valence band to the conduction band, creating
electron-hole pairs. These electron-hole pairs can
participate in electrochemical reactions at the surface of
the semiconductor.

4. . METAL CONTACTS AND P-N JUNCTIONS
SOLID STATE DEVICES GENERALLY REQUIRE METALLIC CONTACTS. THE BEHAVIOR OF THESE CONTACTS IS
NOT ALWAYS PREDICTABLE DUE TO THE PRESENCE OF INTERMEDIATE LAYERS, BUT IN PRINCIPLE THE
TYPE OF CONTACT DEPENDS ON THE ELECTRONIC WORK FUNCTIONS OF THE SEMICONDUCTOR AND THE
METAL. FORMATION OF THE CONTACT INVOLVES ESTABLISHING ELECTRONIC EQUILIBRIUM, SO THAT THE
FERMI LEVELS IN THE METAL AND THE SEMICONDUCTOR MUST BE EQUAL AFTER CONTACT. DURING THE
EQUILIBRATION PROCESS, ELECTRONS ARE TRANSFERRED ACROSS THE JUNCTION AS SHOWN, FOR
EXAMPLE, IN FIGURE 2 FOR AN N-TYPE SEMICONDUCTOR IN CONTACT WITH A METAL THAT HAS A
HIGHER WORK FUNCTION (LOWER FERMI LEVEL). IN THIS CASE, THE EQUILIBRATION OF THE FERMI
LEVELS RESULTS IN FORMATION OF A SCHOTTKY BARRIER, GIVING RISE TO DIODE BEHAVIOR. IF THE
WORK FUNCTION OF THE METAL IS LOWER THAN THAT OF THE N-TYPE SEMICONDUCTOR, ELECTRONS
FLOW IN THE OPPOSITE DIRECTION, AND AN OHMIC CONTACT IS FORMED. IN THE CASE WHERE A
SCHOTTKY BARRIER IS FORMED, THE REMOVAL OF MAJORITY CARRIERS (ELECTRONS) FROM THE
SEMICONDUCTOR GIVES RISE TO A REGION WHERE THE IONIZED DONOR ATOMS IN THE LATTICE
CONSTITUTE AN IMMOBILE SPACE CHARGE. THE WIDTH OF THIS SPACE CHARGE REGION DEPENDS ON
THE DOPING LEVEL, TYPICALLY RANGING FROM 1 MICRON TO 10 NM FOR DOPING DENSITIES OF 1021
TO 1025 M-3 RESPECTIVELY

5. APPLICATIONS OF PHOTOELECTROCHEMISTRY
SOLAR ENERGY CONVERSION: PHOTOELECTROCHEMICAL
CELLS CAN BE USED TO CONVERT SOLAR ENERGY INTO
ELECTRICAL ENERGY.WATER SPLITTING:
PHOTOELECTROCHEMICAL CELLS CAN BE USED TO SPLIT
WATER INTO HYDROGEN AND OXYGEN, WHICH CAN THEN
BE USED AS FUEL.ENVIRONMENTAL REMEDIATION:
PHOTOELECTROCHEMICAL CELLS CAN BE USED TO REMOVE
POLLUTANTS FROM WASTEWATER.

6. PHOTOELECTROCHEMISTRY
PHOTOELECTROCHEMISTRY IS THE STUDY OF THE INTERACTION
BETWEEN LIGHT AND ELECTROCHEMICAL PROCESSES IN
SEMICONDUCTORS. WHEN A SEMICONDUCTOR IS EXPOSED TO LIGHT, IT
GENERATES ELECTRON-HOLE PAIRS WHICH CAN BE USED FOR VARIOUS
ELECTROCHEMICAL REACTIONS.
PHOTOELECTROCHEMICAL CELLS
A PHOTOELECTROCHEMICAL CELL IS A DEVICE THAT UTILIZES LIGHT TO
GENERATE AN ELECTRICAL CURRENT. THIS IS ACHIEVED THROUGH A
PHOTOANODE AND A CATHODE, WHICH ARE TYPICALLY MADE OF
SEMICONDUCTING MATERIALS.

7. SENSORS
SEMICONDUCTOR ELECTROCHEMISTRY HAS ALSO BEEN USED IN
THE DEVELOPMENT OF SENSORS, WHICH DETECT AND MEASURE
THE CONCENTRATION OF VARIOUS SUBSTANCES IN A SAMPLE.
FOR EXAMPLE, SEMICONDUCTOR GAS SENSORS CAN DETECT THE
PRESENCE OF GASES SUCH AS CARBON MONOXIDE, NITROGEN
OXIDES, AND HYDROGEN. THESE SENSORS HAVE APPLICATIONS IN
AIR QUALITY MONITORING, INDUSTRIAL SAFETY, AND MEDICAL
DIAGNOSTICS.

8. SOLAR ENERGY CONVERSION
SEMICONDUCTOR ELECTROCHEMISTRY HAS BEEN APPLIED IN THE DEVELOPMENT OF SOLAR
CELLS, WHICH CONVERT SUNLIGHT INTO ELECTRICAL ENERGY. IN THESE CELLS,
SEMICONDUCTORS ABSORB LIGHT AND GENERATE ELECTRONS THAT ARE COLLECTED BY
ELECTRODES TO PRODUCE ELECTRICITY. THIS TECHNOLOGY HAS THE POTENTIAL TO PROVIDE A
CLEAN AND RENEWABLE SOURCE OF ENERGY.

9. WATER SPLITTING
SEMICONDUCTOR
ELECTROCHEMISTRY HAS ALSO BEEN
APPLIED IN THE PROCESS OF WATER
SPLITTING, WHICH INVOLVES USING
ELECTRICITY TO SPLIT WATER INTO
HYDROGEN AND OXYGEN. THIS
TECHNOLOGY HAS THE POTENTIAL TO
PROVIDE A CLEAN AND RENEWABLE
SOURCE OF HYDROGEN FUEL, WHICH
CAN BE USED IN FUEL CELLS TO
GENERATE ELECTRICITY.

10. SEMICONDUCTOR ELECTROCHEMISTRY IN FUEL CELLS
BASED ON THE FUNDAMENTALS OF SEMICONDUCTOR
ELECTROCHEMISTRY BRIEFLY DISCUSSED IN THE ABOVE SECTION,
WE FURTHER DISCUSS BOTH CONVENTIONAL ION-BASED
ELECTROLYTES AND SEMICONDUCTOR-BASED MEMBRANES FOR
FUEL CELLS, WITH AN EMPHASIS ON HOW SEMICONDUCTOR-IONIC
CONDUCTORS REPLACE CONVENTIONAL IONIC ELECTROLYTES,
RESULTING IN DIFFERENT SCIENTIFIC PRINCIPLES.

11. THANK YOU
VERY MUCH!