Impact of 1, 2-ethanedithiol treatment on luminescence and charge-transport characteristics in colloidal quantum-dot LEDs. (27th September 2019)

• Record Type: Journal Article
• Authors: Nguyen, Huu Tuan; Ryu, Shin Young; Duong, Anh Tuan; Lee, Soonil
• Is Part Of: Nanotechnology. Volume 30:Number 50(2019)
• Publication Date: 2019-09-27
• Subjects: green-emitting CdSe@ZnS -- quantum-dot LED -- 1, 2-ethanedithiol (EDT) treatment -- defect-state passivation -- surface-dipole effect; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ab42dd
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: We report on a substantial increase in luminance and luminous efficiency of green-light emitting devices (LEDs) that use colloidal CdSe@ZnS quantum dots (QDs) as a light-emitting material in response to treatment with 1, 2-ethanedithiol (EDT). The maximum luminance increased from 1146 to 8075 cd m −2, and luminous yield from 0.15 to 1.41 cd A −1 as a result of treating an incomplete device with drops of EDT right after spin-coating QDs onto a ZnO-nanoparticle layer. Based on systematic studies on substrate-dependent change in photoluminescence, and current-voltage and luminance–voltage characteristics, we propose that passivation of intra-gap defect states and relative shifts of energy levels relevant to the operation of QD LEDs are two main results of EDT treatment. In particular, we argue that energy-level shift without emission-color change can be attributed to surface-dipole effects.