Increasing the power conversion efficiency (PCE) of colloidal quantum dot (CQD) solar cells has relied on improving the passivation of CQD surfaces, enhancing CQD coupling and charge transport, and advancing device architecture. The presence of hydroxyl groups on the nanoparticle surface, as well as dimers-fusion between CQDs-has been found to be the major source of trap states, detrimental to optoelectronic properties and device performance. Here, we introduce a CQD reconstruction step that decreases surface hydroxyl groups and dimers simultaneously. We explored the dynamic interaction of charge carriers between band-edge states and trap states in CQDs using time-resolved spectroscopy, showing that trap to ground-state recombination occurs mainly from surface defects in coupled CQD solids passivated using simple metal halides. Using CQD reconstruction, we demonstrate a 60% reduction in trap density and a 25% improvement in charge diffusion length. These translate into a PCE of 12.5% compared to 10.9% for control CQDs.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.nanolett.0c00638DOI Listing

Publication Analysis

Top Keywords

colloidal quantum
8
hydroxyl groups
8
trap states
8
cqd reconstruction
8
cqd
6
trap
5
ligand-assisted reconstruction
4
reconstruction colloidal
4
quantum dots
4
dots decreases
4

Similar Publications

The incorporation of polymeric insulators has led to notable achievements in the field of organic semiconductors. By altering the blending concentration, polymeric insulators exhibit extensive capabilities in regulating molecular configuration, film crystallinity, and mitigation of defect states. However, current research suggests that the improvement in such physical properties is primarily attributed to the enhancement of thin film morphology, an outcome that seems to be an inevitable consequence of incorporating insulators.

View Article and Find Full Text PDF

Low-threshold surface-emitting colloidal quantum-dot circular Bragg laser array.

Light Sci Appl

January 2025

State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Institute of Nanoscience and Applications, Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, China.

Colloidal quantum dots (CQDs) are attractive gain media due to their wavelength-tunability and low optical gain threshold. Consequently, CQD lasers, especially the surface-emitting ones, are promising candidates for display, sensing and communication. However, it remains challenging to achieve a low-threshold surface-emitting CQD laser array with high stability and integration density.

View Article and Find Full Text PDF

Bioengineering chitosan-antibody/fluorescent quantum dot nanoconjugates for targeted immunotheranostics of non-hodgkin B-cell lymphomas.

Int J Biol Macromol

January 2025

Center of Nanoscience, Nanotechnology, and Innovation - CeNano2I, Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, UFMG, Brazil. Electronic address:

B-cell non-Hodgkin lymphoma (NHL) is the most common hematologic malignancy, capable of invading the brain, meninges, and nerve roots of the brain and spine, leading to high lethality. Herein, we designed and developed novel nanostructures for the first time by biofunctionalizing chitosan with two specific antibodies (i.e.

View Article and Find Full Text PDF

Enhancing Optical Properties of Lead-Free CsNaBiCl Nanocrystals via Indium Alloying.

Inorg Chem

January 2025

School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou 213164, PR China.

This study presents the synthesis and characterization of CsNaBiCl nanocrystals (NCs) doped with varying concentrations of In to improve their luminescent properties. Utilizing a colloidal solution method, we systematically varied the In concentration to identify the optimal alloying level for enhancing the photoluminescence (PL) properties of the CsNaBiCl NCs. Structural analysis confirmed that the In-alloyed NCs maintained high crystallinity and a uniform cubic shape.

View Article and Find Full Text PDF

Supercycle Al-Doped ZnMgO Alloys via Atomic Layer Deposition for Quantum Dot Light-Emitting Diodes.

ACS Appl Mater Interfaces

January 2025

Department of Photonics and Nanoelectronics, and BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan 15588, Korea.

Colloidal quantum-dot light-emitting diodes (QD-LEDs) have been significantly improved in terms of device performance and lifetime by employing zinc oxide (ZnO) as an electron transport layer (ETL). Although atomic layer deposition (ALD) allows fabrication of uniform, high-quality ZnO films with minimal defects, the high conductivity of ZnO has hindered its straightforward application as an ETL in QD-LEDs. Herein, we propose fabrication of Al-doped ZnMgO (Al:ZnMgO) ETLs for QD-LEDs through a supercycle ALD, with alternating depositions of various metal oxides.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!