New results on the modulated photocarrier grating technique

Citation
E. Morgado et al., New results on the modulated photocarrier grating technique, J NON-CRYST, 266, 2000, pp. 290-293
Citations number
6
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF NON-CRYSTALLINE SOLIDS
ISSN journal
00223093 → ACNP
Volume
266
Year of publication
2000
Part
A
Pages
290 - 293
Database
ISI
SICI code
0022-3093(200005)266:<290:NROTMP>2.0.ZU;2-Z
Abstract
A modulated photocarrier grating technique (MPG) has been used to measure s ome properties of amorphous silicon samples. The intermediate region where neither the lifetime, tau, nor the dielectric relaxation time, tau(d), are dominant and local charge neutrality may not be maintained has been investi gated. Light intensity dependence of the small-signal Lifetime estimated fr om a modulated photocurrent technique (MPC) was also studied. A qualitative agreement has been found between the data and the MPG theory which shows t hat this technique measures the response time/relaxation time ratio. Based on the results we suggest an overestimate of the ambipolar diffusion length obtained by the steady-state photocarrier grating technique (SSPG) in thes e samples which is an indication that local charge neutrality is not preser ved. (C) 2000 Elsevier Science B.V. All rights reserved.