In:
Journal of Applied Physics, AIP Publishing, Vol. 79, No. 5 ( 1996-03-01), p. 2481-2486
Abstract:
We report laser-induced transient grating experiments performed at room temperature on self-supporting p-type porous silicon films with different porosities. With this technique the diffusion of the photocarriers can be studied with a time resolution of some tens of picoseconds. The gratings were created by two interfering pulses of the second-harmonic radiation from an Nd3+:yttrium-aluminum-garnet YAG laser (2.3 eV) and their decay in time was studied by a time-delayed pulse of the fundamental YAG laser frequency (1.15 eV). The observed grating decay time is very fast (hundreds of picoseconds) and shortens with decreasing porosity. Diffusion constants D=45, 24, and 5 cm2 s−1 have been found for the porosities of 64%, 68%, and 73%, respectively. To explain these high values of D we consider a simple kinetic model which takes into account two different types of carriers, delocalized and trapped ones.
Type of Medium:
Online Resource
ISSN:
0021-8979
,
1089-7550
Language:
English
Publisher:
AIP Publishing
Publication Date:
1996
detail.hit.zdb_id:
220641-9
detail.hit.zdb_id:
3112-4
detail.hit.zdb_id:
1476463-5