Gallium Arsenide Notes

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Gallium Arsenide Notes

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SEMICONDUCTOR DEVICES : 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs)

Introduction to Gallium Arsenide: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33).

Physical properties : 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells.

Structure of GaAs: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour.

Physical Properties of GaAs: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs

Slide 6: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs

Ionization Energy: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs Ionization Energy Group II element can enter the lattice as substitutional impurities, replacing the group III element to become acceptor impurities. Group VI element can enter the lattice substitutionally, replace the group V element to become donor impurities. The ionization energy for the donors in GaAs are smaller than the ionization energy for the acceptor. This is because of the smaller effective mass of the electron compare to that of the hole.

Impurity Ionization Energy in GaAs: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs Ionization Energy Group II element can enter the lattice as substitutional impurities, replacing the group III element to become acceptor impurities. Group VI element can enter the lattice substitutionally, replace the group V element to become donor impurities. The ionization energy for the donors in GaAs are smaller than the ionization energy for the acceptor. This is because of the smaller effective mass of the electron compare to that of the hole. Impurity Ionization Energy in GaAs

Melting point of GaAs: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs Ionization Energy Group II element can enter the lattice as substitutional impurities, replacing the group III element to become acceptor impurities. Group VI element can enter the lattice substitutionally, replace the group V element to become donor impurities. The ionization energy for the donors in GaAs are smaller than the ionization energy for the acceptor. This is because of the smaller effective mass of the electron compare to that of the hole. Impurity Ionization Energy in GaAs Melting point of GaAs The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Under normal conditions of temperature & pressure : (a) compound exists in the solid state (b) melts at a temperature of about 1238°C. The Specific heat of GaAs is 0.33 J g-1°C -1.

Electrical Conductivity: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs Ionization Energy Group II element can enter the lattice as substitutional impurities, replacing the group III element to become acceptor impurities. Group VI element can enter the lattice substitutionally, replace the group V element to become donor impurities. The ionization energy for the donors in GaAs are smaller than the ionization energy for the acceptor. This is because of the smaller effective mass of the electron compare to that of the hole. Impurity Ionization Energy in GaAs Melting point of GaAs The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Under normal conditions of temperature & pressure : (a) compound exists in the solid state (b) melts at a temperature of about 1238°C. The Specific heat of GaAs is 0.33 J g-1°C -1. Electrical Conductivity There is a certain energy region which is not covered by any wavevector in the Brillouin zone . There are just no states available at these energies so-called band gap. States : (a) below the gap called states in the valence band. (b) above the gap are in the conduction band.

Slide 11: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs Ionization Energy Group II element can enter the lattice as substitutional impurities, replacing the group III element to become acceptor impurities. Group VI element can enter the lattice substitutionally, replace the group V element to become donor impurities. The ionization energy for the donors in GaAs are smaller than the ionization energy for the acceptor. This is because of the smaller effective mass of the electron compare to that of the hole. Impurity Ionization Energy in GaAs Melting point of GaAs The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Under normal conditions of temperature & pressure : (a) compound exists in the solid state (b) melts at a temperature of about 1238°C. The Specific heat of GaAs is 0.33 J g-1°C -1. Electrical Conductivity There is a certain energy region which is not covered by any wavevector in the Brillouin zone . There are just no states available at these energies so-called band gap. States : (a) below the gap called states in the valence band. (b) above the gap are in the conduction band. Something that makes gallium arsenide special is the feature marked in orange in the band structure plot. The maximum of the valence band is at the same wave vector as the minimum of the conduction band. This is called a direct gap. GaAs has a higher breakdown voltage than silicon and hence is suitable for operations at higher power levels.

Slide 12: 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs Ionization Energy Group II element can enter the lattice as substitutional impurities, replacing the group III element to become acceptor impurities. Group VI element can enter the lattice substitutionally, replace the group V element to become donor impurities. The ionization energy for the donors in GaAs are smaller than the ionization energy for the acceptor. This is because of the smaller effective mass of the electron compare to that of the hole. Impurity Ionization Energy in GaAs Melting point of GaAs The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Under normal conditions of temperature & pressure : (a) compound exists in the solid state (b) melts at a temperature of about 1238°C. The Specific heat of GaAs is 0.33 J g-1°C -1. Electrical Conductivity There is a certain energy region which is not covered by any wavevector in the Brillouin zone . There are just no states available at these energies so-called band gap. States : (a) below the gap called states in the valence band. (b) above the gap are in the conduction band. Something that makes gallium arsenide special is the feature marked in orange in the band structure plot. The maximum of the valence band is at the same wave vector as the minimum of the conduction band. This is called a direct gap. GaAs has a higher breakdown voltage than silicon and hence is suitable for operations at higher power levels. Electrons can be promoted from the conduction band to the valence band by the absorption of light. At a direct band gap, a crystal can absorb and emit light, much like an isolated atom. The band gap of gallium arsenide at room temperature is 1.43 eV, corresponding to light of the wavelength 870 nm in the near infrared. Thus, gallium arsenide with its direct band gap was one of the first materials used to build light emitting diodes (LEDs) and solid-state lasers.

Credits : 

SEMICONDUCTOR DEVICES Physical Properties ofGallium Arsenide (GaAs) Introduction to Gallium Arsenide Gallium is a chemical element that has the symbol Ga and atomic number 31 Arsenic is a chemical element that has the symbol As and atomic number 33. Is a combination of chemicals Gallium which has the symbol Ga (atomic number 31) with chemical Arsenic that has the symbol As (atomic number 33). Physical properties IUPAC name : Gallium Arsenide Molecular Formula : GaAs Molar mass : 144.645 g/mol Is known to be toxic in nature. Is a carcinogenic substance as well. Is used to make devices such as microwave frequency integrated, infrared light-emitting diodes, laser diodes and solar cells. Structure of GaAs Crystal structure of GaAs similar to Zinc blende where cubic zinc structure in which the sulfide ions form a face-centered cubic array and the zinc ions fill one-half of the tetrahedral holes. Crystals of gallium arsenide are cubic in shape and dark grey in colour. Physical Properties of GaAs Ionization Energy Group II element can enter the lattice as substitutional impurities, replacing the group III element to become acceptor impurities. Group VI element can enter the lattice substitutionally, replace the group V element to become donor impurities. The ionization energy for the donors in GaAs are smaller than the ionization energy for the acceptor. This is because of the smaller effective mass of the electron compare to that of the hole. Impurity Ionization Energy in GaAs Melting point of GaAs The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. Under normal conditions of temperature & pressure : (a) compound exists in the solid state (b) melts at a temperature of about 1238°C. The Specific heat of GaAs is 0.33 J g-1°C -1. Electrical Conductivity There is a certain energy region which is not covered by any wavevector in the Brillouin zone . There are just no states available at these energies so-called band gap. States : (a) below the gap called states in the valence band. (b) above the gap are in the conduction band. Something that makes gallium arsenide special is the feature marked in orange in the band structure plot. The maximum of the valence band is at the same wave vector as the minimum of the conduction band. This is called a direct gap. GaAs has a higher breakdown voltage than silicon and hence is suitable for operations at higher power levels. Electrons can be promoted from the conduction band to the valence band by the absorption of light. At a direct band gap, a crystal can absorb and emit light, much like an isolated atom. The band gap of gallium arsenide at room temperature is 1.43 eV, corresponding to light of the wavelength 870 nm in the near infrared. Thus, gallium arsenide with its direct band gap was one of the first materials used to build light emitting diodes (LEDs) and solid-state lasers. Credits GROUP 4 HO JIA HUN 138255 TIOH PEE LING 138691 THAM TZI LEN 139239 CHAY KWOK MAN 138105 LEE SOON LI 130617 HAN SHIN YING 129980 AZILAH AMRAN 132333 IYLIA SYAZANA OTHMAN 131109 NOR SYAHIDA MOHIDIN 136679