Fabrication and Characterization of Multi-Shell Structure Quantum dot Doping Organic Scintillator

Su Jung Min¹, Hyun Soo Kim², Heung Su Joung², Bum Kyoung Seo¹, Chang Hyun Roh¹, Sang Bum Hong^1,*

¹Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea
²Global ZEUS, 132, Annyeongnam-ro, Hwaseong-si, Gyeonggi-do 18363, Republic of Korea

Received 2024-10-28 ; Revised 2024-11-12 ; Approved 2024-12-09

Abstract

A scintillator using organic materials can be easily manufactured in various shapes and sizes to suit the user's purpose. A quantum dot (QD)-based scintillator has a number of advantages over commercial scintillators, including emission wavelength control, high-purity emission of a specific wavelength, high photoluminescence efficiency, and good photostability. The organic scintillators doping with various agents into the polymer media to increase scintillation efficiency and to control the emissioning wavelength through energy transfer process. In this study, scintillator enhancement was observed with different QDs material and detection response to gamma and neutron was investigated in energy spectrum. Multi-shell-structure QDs (CdS/CdZnS/ZnS) were fabricated and utilized to offset the shortcomings of single-shell-structure QDs, and the optical properties and the gamma and neutron detection performance capabilities were evaluated. The results of the evaluation of the detection response of the QD-based scintillator confirmed that the neutron/gamma classification performance was similar to that of a commercial scintillator. Furthermore, the gamma detection efficiency was improved by 34–38% (in the case of 137Cs) compared to a commercial scintillator. This study is especially notable in that the organic scintillator incorporated with the newly fabricated QDs can be utilized for gamma and neutron detection for the operation and decommissioning various nuclear facilities.

Key Words : Quantum dot (QD), Solid/Liquid scintillator, Detection efficiency, Gamma detection, Neutron/Gamma identification (PSD)