Halide-Based Inkification of Amino-Arsine–Based InAs Quantum Dots for SWIR Photodetectors

Jae Taek Oh^a, Taewan Kim^a, Hao Wu^a, Marta Martos Valverde^a, Gerasimos Konstantatos^a^,^b

^aICFO–Insitut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain

^bICREA–Institució Catalana de Recerca i Estudiats Avançats, Lluis Companys 23, Barcelona, 08010, Spain

Proceedings of MATSUS Spring 2026 Conference (MATSUSSpring26)

C2 Advances in low-dimensional Nanocrystals: Fundamental approaches and technological perspectives

Barcelona, Spain, 2026 March 23rd - 27th

Organizers: Zhuoying Chen, Fabian Paulus, Carmelita Rodà and Matteo Zaffalon

Poster, Jae Taek Oh, 970
Publication date: 15th December 2025

Indium arsenide colloidal quantum dots (InAs CQDs) synthesized from amino-arsine (amino-As) precursors offer a cost-effective and scalable alternative to conventional organoarsine-based routes for short-wave infrared (SWIR) optoelectronics. Despite these advantages, amino-As–based InAs CQDs have predominantly relied on thiol-based solid-state ligand exchange for device fabrication, which limits effective surface passivation and the scalability of InAs CQD-based optoelectronic devices.

Here, we demonstrate a halide-based inkification strategy for amino-As–based InAs CQDs, enabling the formulation of conductive, solution-processable CQD inks. This surface chemical reconstruction effectively removes insulating native ligands and suppresses surface trap states present in as-synthesized InAs CQDs, leading to improved electronic coupling in CQD films and efficient photodiode operation.

SWIR photodiodes fabricated using the halide-passivated InAs CQD inks exhibit a peak external quantum efficiency (EQE) of 19.1% at 1300 nm. By tuning the CQD size, maximum EQE values of 17.3% at 1410 nm and 13.9% at 1470 nm were achieved, demonstrating consistent high performance across the extended SWIR spectral range. The devices further exhibit a specific detectivity of 1.42 × 10¹⁰ Jones, highlighting the general applicability of this halide-based ink platform.

These results establish halide-based ink engineering as a viable pathway to scalable, high-performance SWIR photodetectors based on amino-As–synthesized InAs CQDs.

Acknowledgements:

G.K. acknowledges financial support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 101002306), the European Union under grant agreement No 101119489 (2DNeuralvision) and Project PID2024-161119OB-I00 funded by MICIU/AEI/ 10.13039/501100011033/FEDER, UE. We also acknowledge support from the Fundació Privada Cellex, the program CERCA and ‘Severo Ochoa’ Centre of Excellence. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them.

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