Donor Levels In Gap Research Articles

Electrical field effect on both thermal ionization energy and optical threshold energy of the Cr 3+/4+ deep donor level in GaP

The effect of the electric field on both thermal ionization energy and optical threshold energy have been studied using deep level transient spectroscopy (DLTS) and electrical deep level optical spectroscopy (Electrical DLOS) techniques in Cr-doped GaP. The measurements were focused on the Cr 3+/ 4+ donor level. It is found that the ionization energy E i decreases with the electrical field F as in the case of the Poole–Frenkel model. It is found that there is a variation of the optical threshold with the electrical field.

Poole–Frenkel effect assisted emission from deep donor level in chromium doped GaP

The electrical properties of chromium-related defects in GaP are investigated. Using deep-level transient spectroscopy, a related deep level is observed in p-type GaP exhibiting an activation energy, associated with hole emission, of 0.5 eV. Detailed capacitance transient investigations were undertaken to study the electric field dependence. This emission rate which is found to have a field dependence can be fitted by a Poole–Frenkel model. Evidence is given that the trap is the Cr4+/3+ deep donor level in GaP caused by substitutional Cr on Ga sites. This trap seems to be well adapted to compensate donors for the growth of the semi-insulating GaP.

Identification of the Ti donor level in GaP

Isothermal capacitance transient spectroscopy (ITS) has been applied to study p-type Ti-doped GaP at temperatures as high as 430 K. A deep level with an apparent activation energy of 1.15+or-0.06 eV has been detected and identified as the Ti3+/Ti4+ donor level. This assignation is based on the optical photoneutralization threshold of 0.92+or-0.02 eV, which agrees with previous photoelectron paramagnetic resonance (EPR) results and the agreement between the level concentration and secondary-ion mass spectroscopy (SIMS) measurements of Ti content.

Pressure dependence of donor levels in GaP: electronic Raman scattering experiments : G. Galtier and G. Martinez. Solid St. Commun.65, 193 (1988)

This paper describes a method for calculating under low-level injection conditions the minority carrier current in a heavily-doped diffused region, examples of which are the emitter region of a double-diffused transistor and the diffused regions of a p-L-n rectifier or a thyristor. Based on the assumption that the minority-carrier quasi-Fermi potential is constant, the method is simpler and has wider applicability than that given by Klein. For the three standard types of impurity profiles — the exponential, the Gaussian, and the erfc, it yields a common expression for the minority carrier current Jp at the junction edge, namely Jp = qp[τp0(qEkT)], where p and E are, respectively, the minority carrier concentration and field at the junction edge, τp0 the minority carrier lifetime, and (kTq) the thermal voltage. The basis of the constant quasi-Fermi potential assumption is examined, and conditions for its validity are derived.The validity of the treatment presented is verified by exact numerical solutions for a n+−p−p+ diffused junction rectifier whose n+-region has a doping profile of the erfc type.

Pressure dependence of donor levels in GaP: Electronic Raman scattering experiments

Abstract Electronic Raman scattering experiments have been performed in S and Te doped GaP up to 47 kbar. We observe an increase of the energy of the 1S(Γ 1 )-1S(Γ 12 ) intergroundstate transition. Its pressure coefficient is very small and suggests that the 1S(Γ 1 ) donor ground state evoluate like a shallow level. The results are analyzed in terms of lattice parameter, screening, effective mass and umklapp parameter variations.

Higher Donor Excited States for Prolate-Spheroid Conduction Bands: A Reevaluation of Silicon and Germanium

An extension of the Kohn-Luttinger method for the energy levels of the effective-mass Hamiltonian $H=(\frac{P_{x}^{2}}{2{m}_{\ensuremath{\perp}}}+\frac{P_{y}^{2}}{2{m}_{\ensuremath{\perp}}}+\frac{P_{z}^{2}}{2{m}_{\ensuremath{\parallel}}})\ensuremath{-}\frac{{e}^{2}}{\mathrm{Kr}}$ is made via the Rayleigh-Ritz approach. The method is capable of indefinite extension provided one is prepared to deal with large matrices. The first nine $S$-like energy levels and the first eighteen $P$-like energy levels are presented here as a function of the mass ratio $\ensuremath{\gamma}=\frac{{m}_{\ensuremath{\perp}}}{{m}_{\ensuremath{\parallel}}}$ for $0<\ensuremath{\gamma}\ensuremath{\le}1$. The experimental results for the $P$-like excited states of silicon and germanium can be fitted to within experimental error if one takes the low-temperature static dielectric constant of silicon to be 11.40\ifmmode\pm\else\textpm\fi{}0.05, and that of germanium to be 15.36\ifmmode\pm\else\textpm\fi{}0.05. The situation concerning donor levels in GaP is discussed briefly.

Valley-Orbit Splitting of Donor Level in GaP

Valley-Orbit Splitting of Donor Level in GaP