View : 124 Download: 0

Enhanced thermal stability of InP quantum dots coated with Al-doped ZnS shell

Title
Enhanced thermal stability of InP quantum dots coated with Al-doped ZnS shell
Authors
Koh, SungjunLee, HyeonjunLee, TaeminPark, KyoungwonKim, Woo-JaeLee, Doh C.
Ewha Authors
김우재
Issue Date
2019
Journal Title
JOURNAL OF CHEMICAL PHYSICS
ISSN
0021-9606JCR Link

1089-7690JCR Link
Citation
JOURNAL OF CHEMICAL PHYSICS vol. 151, no. 14
Publisher
AMER INST PHYSICS
Indexed
SCIE; SCOPUS WOS scopus
Document Type
Article
Abstract
Colloidal InP quantum dots (QDs) have attracted a surge of interest as environmentally friendly light-emitters in downconversion liquid crystal displays and light-emitting diodes (LEDs). A ZnS shell on InP-based core QDs has helped achieve high photoluminescence (PL) quantum yield (QY) and stability. Yet, due to the difficulty in the growth of a thick ZnS shell without crystalline defects, InP-based core/shell QDs show inferior stability against QY drop compared to Cd chalcogenide precedents, e.g., CdSe/CdS core/thick-shell QDs. In this work, we demonstrate the synthesis of InP-based core/shell QDs coated with an Al-doped ZnS outer shell. QDs with an Al-doped shell exhibit remarkable improvement in thermal and air stability even when the shell thickness is below 2 nm, while the absorption and PL spectra, size, and crystal structure are nearly the same as the case of QDs with a pristine ZnS shell. X-ray photoelectron spectroscopy reveals that Al3+ in Al-doped QDs forms an Al-oxide layer at elevated temperature under ambient atmosphere. The as-formed Al-oxide layer blocks the access of external oxidative species penetrating into QDs and prevents QDs from oxidative degradation. We also trace the chemical pathway of the incorporation of Al3+ into ZnS lattice during the shell growth. Furthermore, we fabricate QD-LEDs using Al-doped and undoped QDs and compare the optoelectronic characteristics and stability.
DOI
10.1063/1.5121619
Appears in Collections:
엘텍공과대학 > 화학신소재공학전공 > Journal papers
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE