Transient Rayleigh scattering: A new probe of picosecond carrier dynamics in a single semiconductor nanowire

Date

2012

Authors

Montazeri, Mohammad
Jackson, Howard E
Smith, Leigh M
Yarrison-Rice, Jan M
Kang, Jung-Hyun
Gao, Qiang
Jagadish, Chennupati
Tan, Hark Hoe

Journal Title

Journal ISSN

Volume Title

Publisher

American Chemical Society

Abstract

Using a new technique, transient Rayleigh scattering, we show that measurements from a single GaAs/AlGaAs core-shell semiconductor nanowire provide sensitive and detailed information on the time evolution of the density and temperature of the electrons and holes after photoexcitation by an intense laser pulse. Through band filling, band gap renormalization, and plasma screening, the presence of a dense and hot electron-hole plasma directly influences the real and imaginary parts of the complex index of refraction that in turn affects the spectral dependence of the Rayleigh scattering cross-section in well-defined ways. By measuring this spectral dependence as a function of time, we directly determine the thermodynamically independent density and temperature of the electrons and holes as a function of time after pulsed excitation as the carriers thermalize to the lattice temperature. We successfully model the results by including ambipolar transport, recombination, and cooling through optic and acoustic phonon emission that quantify the hole mobility at ∼68,000 cm 2/V·s, linear decay constant at 380 ps, bimolecular recombination rate at 4.8 × 10 -9 cm 3/s and the energy-loss rate of plasma due to optical and acoustic phonon emission.

Description

Keywords

Keywords: Acoustic phonons; Ambipolar transport; Band fillings; Band gap renormalization; Bimolecular recombination; Carrier cooling; Carrier dynamics; Complex index of refraction; Core-shell; Decay constants; Electron hole plasma; Electrons and holes; Energy-loss carrier cooling; carrier dynamics; Nanowire; transient Rayleigh scattering

Citation

Source

Nano Letters

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1021/nl302767u

Restricted until

2037-12-31