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 present a halide-based solution-phase ligand exchange strategy for amino-As–based InAs CQDs that enables the formulation of conductive, solution-processable CQD inks. The inkification process removes insulating native ligands and passivates surface trap states in as-synthesized InAs CQDs, thereby enhancing interdot electronic coupling in CQD films and enabling efficient photodiode operation.

SWIR photodiodes fabricated using halide-passivated InAs CQD inks exhibit a peak external quantum efficiency (EQE) of 19.1% at 1300 nm and a specific detectivity exceeding 10¹⁰ Jones. 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 and confirming the versatility and general applicability of this halide-based ink platform for broadband SWIR photodetection applications.

These results establish halide-based ink platform as a scalable and robust pathway toward high-performance SWIR photodetectors based on amino-As–derived 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.

nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.

MATSUS

Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.

International Conference on Hybrid and Organic Photovoltaics

International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.

Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics

The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.

International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics

The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.