ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Stretched Exponential Relaxation of Persistent Photoconductivity Due to the Si-Related DX Centre in $Al_xGa_{1-x}As$

Ghosh, S and Kumar, V (1993) Stretched Exponential Relaxation of Persistent Photoconductivity Due to the Si-Related DX Centre in $Al_xGa_{1-x}As$. In: Europhysics Letters, 24 (9). pp. 779-784.

[img] PDF
fulltext.pdf
Restricted to Registered users only

Download (469Kb) | Request a copy

Abstract

We have shown that the decay of the photoexcited carrier after termination of disequilibrating illumination follows the stretched-exponential-relaxation law $n(t) = n(0) exp[ - (t/\tau)^{\beta}]$. It is found that the stretching parameter $\beta$and relaxation time constant z depend on temperature with \beta ranging from 0.2 to 0.4. The stretched exponential relaxation is attributed to the capture-enhanced motion of an Si donor atom from the substitutional to an interstitial site in an $Al_xGa_{1-x}As$ lattice during the capture of photoexcited electrons from the conduction band.Temperature-dependent $\beta$ is associated with the distribution of activation energies due to local atomic alloy disorder in $Al_xGa_{1-x}As$. The distribution of activation energies is also verified with the novel spectroscopic technique based on deep-level transient spectroscopy.

Item Type: Journal Article
Additional Information: Copyright of this article belongs to Institute of Physics.
Department/Centre: Division of Physical & Mathematical Sciences > Physics
Date Deposited: 02 Jul 2008
Last Modified: 19 Sep 2010 04:46
URI: http://eprints.iisc.ernet.in/id/eprint/14637

Actions (login required)

View Item View Item