Anomalous reduction in the energy loss of electrons in p-type semiconductors

We study femtosecond relaxation of minority carriers (electrons) injected into a heavily p-doped base of a heterojunction bipolar transistor (HBT). Here, we consider the case of p-doped GaAs, to be specific. The electrons are assumed to have a peaked energy distribution at t=0, with kinetic energies a few hundred meV above the conduction band threshold. We solve the time dependent Boltzmann equation governing the dynamics of these electrons. The main feature of this work is a detailed calculation of the time dependent nonthermal, nonequilibrium electron energy distribution, that relaxes due to single particle excitations via electron–hole scattering and interaction with coupled optical phonon-hole plasmon modes in the sub and picosecond time domains. We highlight the significant role that the electron-hole scattering plays in this relaxation. The majority carriers (holes) are assumed to remain in quasiequilibrium with the lattice, taken to be at room temperature (or at 77 K). We present calculations of electron energy relaxation with the hole density varied from 1×1018 to 1×1020 cm−3. In the initial, subpicosecond stages of the relaxation, the energy distribution evolves into two major components: a quasiballistic but broad component, at energies near the injection energy, and an energy relaxed component near E=0. The latter becomes dominant in a picosecond or so. The electrons with an initial mean velocity of ∼1.5×108 cm/s attain a cooler distribution with a mean velocity of ∼4×107 cm/s within about 1 ps for p doping in excess of 1×1019 cm−3. The temporal evolution of average velocity 〈v〉 of the electrons should be useful in obtaining values of the base width suitable for effective operation of HBTs.

show abstract

Ferromagnetic resonant interband tunneling diode

Vurgaftman

Meyer

2003

Applied Physics Letters

View full text Add to dashboard Cite

We consider the spin-polarizing properties of a ferromagnetic resonant interband tunneling diode based on the type-II InAs/(AlSb)/GaMnSb/(AlSb)/InAs heterostructure system. The current–voltage characteristics are simulated using the effective bond-orbital method, in conjunction with self-consistent treatments of both the electrostatic potential and the magnetic exchange interaction. We find that the device can be employed as either a source of spin-polarized electrons, whose polarity varies with applied bias, or as a spin valve. For example, the polarization of electrons tunneling to the collector from an unpolarized emitter can exceed 75% in either direction.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Anomalous reduction in the energy loss of electrons in p-type semiconductors

Cited by 4 publications

References 11 publications

Reduced Cooling Rates of Electrons in Degenerately p-Doped GaAs

Reduced Cooling Rates of Electrons in Degenerately p-Doped GaAs

Femtosecond energy relaxation of nonthermal electrons injected in p-doped GaAs base of a heterojunction bipolar transistor

Ferromagnetic resonant interband tunneling diode

Contact Info

Product

Resources

About