Question

Q.1 (a) GaP has an indirect bandgap of 2.26 eV and its relative dielectric constant ?r = 10. Calculate the photon energy (in eV) of a shallow donor to shallow acceptor transition in GaP if the donor and acceptor impurity separation is 20 Å. Given the donor and acceptor energy levels at ground states of GaP are 0.107 eV and 0.210 eV, respectively. (b) Burstein-Moss shift (BMS) is the phenomenon of which the Fermi level moves into the conduction band in degenerate semiconductors. As a result, the absorption edge shifts to a higher energy as doping concentration increases. Give two reasons why you could not make GaAs with a bandgap of 1.43 eV to emit in the wavelength of 400 nm by simply increasing the doping concentration. The electron and hole effective masses of GaAs are given as me* = 0.067m? and mh* = 0.54 m?, respectively. (c) The conduction band (CB) minimum of Si occurs at the (100) valley and has a wave-vector k(0.85, 0, 0) 2?/a where the lattice constant a = 0.5431 nm. A conduction band electron in Si is located in the (100) valley and has a wave-vector k(1.0, 0.1, 0.1) 2?/a. The longitudinal and transverse effective masses of electron are 0.98m? and 0.19m?, respectively, where m? is the electron rest mass. Calculate the energy of this electron measured from the CB minimum. (d) InN semiconductor has a direct bandgap of 0.77 eV and a relative dielectric constant ?r = 15.3. The electron and hole effective masses of InN are me* = 0.11m? and mh* = 1.63 m?, respectively. (i) Calculate the InN free exciton binding energy and its exciton Bohr radius. (ii) Estimate the temperature in which the exciton will be dissociated into an unbound electron-hole pair. (e) Explain what are physical properties determine the critical layer thickness of a semiconductor alloy to be epitaxially grown on a substrate

          Q.1 (a) GaP has an indirect bandgap of 2.26 eV and its relative dielectric constant ?r = 10. Calculate the photon energy (in eV) of a shallow donor to shallow acceptor transition in GaP if the donor and acceptor impurity separation is 20 Å. Given the donor and acceptor energy levels at ground states of GaP are 0.107 eV and 0.210 eV, respectively.

(b) Burstein-Moss shift (BMS) is the phenomenon of which the Fermi level moves into the conduction band in degenerate semiconductors. As a result, the absorption edge shifts to a higher energy as doping concentration increases. Give two reasons why you could not make GaAs with a bandgap of 1.43 eV to emit in the wavelength of 400 nm by simply increasing the doping concentration. The electron and hole effective masses of GaAs are given as me* = 0.067m? and mh* = 0.54 m?, respectively.

(c) The conduction band (CB) minimum of Si occurs at the (100) valley and has a wave-vector k(0.85, 0, 0) 2?/a where the lattice constant a = 0.5431 nm. A conduction band electron in Si is located in the (100) valley and has a wave-vector k(1.0, 0.1, 0.1) 2?/a.
The longitudinal and transverse effective masses of electron are 0.98m? and 0.19m?, respectively, where m? is the electron rest mass. Calculate the energy of this electron measured from the CB minimum.

(d) InN semiconductor has a direct bandgap of 0.77 eV and a relative dielectric constant ?r = 15.3. The electron and hole effective masses of InN are me* = 0.11m? and mh* = 1.63 m?, respectively.

(i) Calculate the InN free exciton binding energy and its exciton Bohr radius.

(ii) Estimate the temperature in which the exciton will be dissociated into an unbound electron-hole pair.

(e) Explain what are physical properties determine the critical layer thickness of a semiconductor alloy to be epitaxially grown on a substrate

Q.1 (a) GaP has an indirect bandgap of 2.26 eV and its relative dielectric constant ?r = 10. Calculate the photon energy (in eV) of a shallow donor to shallow acceptor transition in GaP if the donor and acceptor impurity separation is 20 Å. Given the donor and acceptor energy levels at ground states of GaP are 0.107 eV and 0.210 eV, respectively.

(b) Burstein-Moss shift (BMS) is the phenomenon of which the Fermi level moves into the conduction band in degenerate semiconductors. As a result, the absorption edge shifts to a higher energy as doping concentration increases. Give two reasons why you could not make GaAs with a bandgap of 1.43 eV to emit in the wavelength of 400 nm by simply increasing the doping concentration. The electron and hole effective masses of GaAs are given as me* = 0.067m? and mh* = 0.54 m?, respectively.

(c) The conduction band (CB) minimum of Si occurs at the (100) valley and has a wave-vector k(0.85, 0, 0) 2?/a where the lattice constant a = 0.5431 nm. A conduction band electron in Si is located in the (100) valley and has a wave-vector k(1.0, 0.1, 0.1) 2?/a.
The longitudinal and transverse effective masses of electron are 0.98m? and 0.19m?, respectively, where m? is the electron rest mass. Calculate the energy of this electron measured from the CB minimum.

(d) InN semiconductor has a direct bandgap of 0.77 eV and a relative dielectric constant ?r = 15.3. The electron and hole effective masses of InN are me* = 0.11m? and mh* = 1.63 m?, respectively.

(i) Calculate the InN free exciton binding energy and its exciton Bohr radius.

(ii) Estimate the temperature in which the exciton will be dissociated into an unbound electron-hole pair.

(e) Explain what are physical properties determine the critical layer thickness of a semiconductor alloy to be epitaxially grown on a substrate

Added by Gonzalo S.

Question

Please give Ace some feedback