Enhancement of IR photoluminescence of β‐FeSi2 nanocrystals by Cu‐doping and study of its mechanism. Issue 11 (25th July 2014)

• Record Type: Journal Article
• Authors: Maeda, Yoshihito; Tatsumi, Takahide; Kawakubo, Yuki; Noguchi, Yuya; Kobayashi, Hiroyuki; Narumi, Kazumasa; Sakai, Seiji; Pizzini, Sergio; Kissinger, Gudrun
• Is Part Of: Physica status solidi. Volume 11:Issue 11/12(2014)
• Page Start: 1626
• Page End: 1629
• Publication Date: 2014-07-25
• Subjects: Solid state physics -- Congresses; Solid state physics -- Periodicals; Solid state physics; Conference proceedings; Periodicals; 530.41
• DOI: 10.1002/pssc.201400039
• Languages: English
• ISSNs: 1862-6351

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>We have investigated the IR photoluminescence (PL) behavior of Cu‐doped β‐FeSi₂ nanocrystals (β‐NCs) embedded in Si layers. The diffusion rate of Cu atom was controlled by annealing. The most appropriate condition brought the largest intensities of both the intrinsic A band emission at 0.803 eV by 214% and the acceptor related C band emission at ∼0.75 eV by 582% in comparison with those of non‐doped β‐NCs. Rutherford backscattering spectrometry (RBS) revealed increase of Cu atoms in the Si layer with β‐NCs with increasing the anneal duration.</p> <p>The C band enhancement surely is originated from increase of a density of state at acceptor levels relating to increase of Cu in β‐lattice. Photocarrier injection PL measurements (PCI‐PL) reveal that the enhancement of the A band emission may be attributed to a controlled migration process of holes with a repeated trap process due to Cu‐doping into the Si phase. This dynamic condition leads to an increase of valence band offset at the β‐NCs/Si heterointerfaces where the migration of holes from the β‐NCs to Si is prevented, so that a radiative recombination rate can be enhanced. (© 2014 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)</p> </abstract>