標題: Origin of localized states in zinc-blende ZnCdSe thin films and the influence on carrier relaxation of self-assembled ZnTe/ZnCdSe quantum dots
作者: Lee, Ling
Dai, Yue-Ru
Yang, Chu-Shou
Fan, Wen-Chung
Chou, Wu-Ching
電子物理學系
Department of Electrophysics
關鍵字: Semiconductors;Nanostructured materials;Vapor deposition;Optical properties;Time-resolved optical spectroscopies
公開日期: 25-May-2015
摘要: This study discovered the origin of deep level emission in zinc-blende ZnCdSe thin films grown by molecular beam epitaxy, in which a localization behavior was noticed. Pronounced deep level emission observed in films grown under a VI/II ratio of 1.74 (Se-accumulated regime) could be suppressed by a lower VI/II ratio of 1.04 (intermediate regime) and 0.74 (metal-rich regime). Hence the localized states could be correlated to excess selenium accumulated at the growth surface. The localized states also influence the carrier relaxation process of self-assembled ZnTe quantum dots embedded in a ZnCdSe matrix. Once quantum dots surmount the wetting layer, localized electrons in the capping layer dominate the type-II transition and exhibit size-independent lifetimes. (C) 2015 Elsevier B.V. All rights reserved.
URI: http://dx.doi.org/10.1016/j.jallcom.2015.01.268
http://hdl.handle.net/11536/124441
ISSN: 0925-8388
DOI: 10.1016/j.jallcom.2015.01.268
期刊: JOURNAL OF ALLOYS AND COMPOUNDS
Volume: 632
起始頁: 392
結束頁: 396
Appears in Collections:Articles