# Efficient and Pure I-III-VI AIGS Quantum Dot-Based Light-Emitting Diodes via Ligand-Reshaped Surface State

## TL;DR

Researchers improved the performance of AIGS quantum dot LEDs by reshaping their surface with a special ligand, achieving high efficiency and pure color.

## Contribution

A novel ligand-reshaped strategy using dimercaptosuccinic acid to enhance AIGS quantum dot performance in LEDs.

## Key findings

- DSA passivation reduced non-radiative recombination and improved photoluminescence quantum yield to 89%.
- The reshaped AIGS QLEDs achieved a record peak external quantum efficiency of 8.4%.
- The method enabled pure emission with a narrow full width at half maximum of 31 nm.

## Abstract

A ligand reshaped strategy is proposed to optimize the surface state of silver indium
gallium sulfide (AIGS) quantum dots (QDs) via a polyfunctional ligand,
mercaptosuccinic acid.Both donor–acceptor pair and non radiative recombination pathways are decreased after
passivation, which leads to a notable narrowing full width at half maximum to 31 nm and
an enhancement of photoluminescence quantum yield up to 89%.The efficient and pure QD based light emitting diodes (QLEDs) exhibit a maximum
peak external quantum efficiency of 8.4%, representing the record performance of AIGS QLEDs.

A ligand reshaped strategy is proposed to optimize the surface state of silver indium
gallium sulfide (AIGS) quantum dots (QDs) via a polyfunctional ligand,
mercaptosuccinic acid.

Both donor–acceptor pair and non radiative recombination pathways are decreased after
passivation, which leads to a notable narrowing full width at half maximum to 31 nm and
an enhancement of photoluminescence quantum yield up to 89%.

The efficient and pure QD based light emitting diodes (QLEDs) exhibit a maximum
peak external quantum efficiency of 8.4%, representing the record performance of AIGS QLEDs.

The online version contains supplementary material available at 10.1007/s40820-026-02086-y.

The I-III-VI silver indium gallium sulfide (AIGS) quantum dots (QDs) have gained extensive attention owing to their tunable emission wavelength and ecofriendly composition; however, the performance of AIGS QD-based light-emitting diodes (QLEDs) remains constrained by suboptimal surface state, significantly lagging behind that of other heavy-metal-containing QD counterparts. Herein, we propose a ligand-reshaped strategy aimed at optimizing the surface state of AIGS QDs to enhance the performance of QLEDs. A polyfunctional ligand, dimercaptosuccinic acid (DSA), is introduced to reshape the QD surface through passivation of uncoordinated Ga3+ and suppression of S vacancies. After DSA passivation, the QDs exhibit not only exceptional luminescent properties with a photoluminescence quantum yield of 89%, but also pure emission with a narrow full width at half maximum of 31 nm. Concurrently, DSA passivation markedly improves the electrical transport characteristic of QDs, thereby ensuring efficient carrier injection. Resultantly, the reshaped QLED achieves a maximum peak external quantum efficiency of 8.4% along with a narrow FWHM of 31 nm, representing a record performance reported thus far for the AIGS system. The proposed DSA ligand-reshaped strategy endows AIGS QLEDs with both high efficiency and color purity, substantially advancing their potential for the application in QD lightings and display technologies .

The online version contains supplementary material available at 10.1007/s40820-026-02086-y.