NIRLUMIN · RoHS compliant, high luminescence, heterostructure nanocrystals for near infrared LEDs and bioimaging.
Horizon Europe — Marie Skłodowska-Curie Actions
- Duration
- 2023-06-01 → 2025-05-31
- EU contribution
- €189,687
- Participants
- 1
- Scheme
- HORIZON-TMA-MSCA-PF-EF
Lines connect the coordinator with its partners.
Results in brief
RoHS compliant, high luminescence, heterostructure nanocrystals for near infrared LEDs and bioimaging.
Context and Motivation The research towards the advancement of semiconductor quantum dots (QDs) that are efficient emitters in the near-infrared (NIR) or short-wave infrared (SWIR) region are of paramount importance for NIR-based technologies, including biomedical imaging, telecommunications, night-vision sensors, health monitoring food inspection, and energy-efficient lighting. However, most of the efficient NIR-emitting QDs reported, rely on toxic heavy metals like lead (Pb) and mercury (Hg), which are restricted under the European Restriction of Hazardous Substances (RoHS) directive. This regulatory constraint, combined with growing environmental and health concerns, has created an urgent need for RoHS-compliant, high-performance alternatives that match or surpass the optical properties of Pb/Hg-based QDs. Existing heavy-metal-free alternatives, such as I-III-VI (e.g., CuInS2, AgInSe2) and III-V (e.g., InAs) QDs, suffer from key limitations: • Low photoluminescence quantum yield (PLQY) beyond 1000 nm. • Broad emission linewidths (>150 meV), reducing spectral precision. • Limited tunability across the SWIR range (1000–1400 nm). This project, NIRLUMIN, addresses these challenges by developing novel heterostructured QDs based on I-III-VI, Cu-Zn-In-Se (CZISe) with engineered shells (ZnS/Al2O₃) to achieve high efficiency, narrow emission, and environmental stability—while remaining fully RoHS-compliant. Overall Objectives The project’s primary goal was to design, synthesize, and optimize heavy-metal-free efficient NIR-emitting QDs as a potential alternative to the Pb/Hg-based QDs. Specific objectives included: • Synthesis and development of I-III-VI-based QDs via partial cation exchange, enabling precise control over morphology (triangular, spherical, cubic) and size. • Enhancement of optical properties and stability through core-shell engineering targeting: high PLQY, tunable emission beyond 1000 nm with narrow emission linewidth and long term stability. • For biocompatibility, encapsulate the core-shell QDs with a ceramic-type shell of alumina (Al2O3) to provide further passivation and prevent degradation of the nanocrystals in different environments as well as the associated leaching out of metal ions, which can have toxic effects (e.g., zinc). • Surface functionalization for compatibility with optoelectronic devices (LEDs, sensors) and biomedical applications (aqueous dispersion). • Proof-of-concept integration into NIR-LEDs and down-conversion systems.
Data: CORDIS, © European Union
Project objective
Colloidal nanocrystals (NCs) that absorb and emit in the near-infrared (NIR) region are of paramount importance in the field of optoelectronics (LEDs, LASERs, solar cells, telecommunication) and biological imaging. However, most of the NIR emitting NCs are based on heavy metals (Pb, Cd, Hg) which are highly toxic and are restricted from widespread use by the European regularity concerns. Therefore, the development of NIR emitting environmentally friendly (Cd/Pb/Hg- free) NCs are of interest. NIRLUMIN proposes a strategy to develop high NIR (1-1.35um) luminescent, stable AInTe2/(Ga/In)2S3/Zn(S/Se) core/shell/shell (CSS) NC heterostructures with controlled bandgap and size in which the outer shells will protect the surface of the core and enhance the photoluminescence quantum yield by passivating the dangling bonds and surface traps while the intermediate layer will stop diffusion to prevent the undesirable bandgap enhancement. Further, the advantages of these NCs will be directly translated into device performance in the LED. For biological imaging, these nanostructures will be over-coated with a ceramic-type alumina shell and transferred to the aqueous phase. The whole work will be conducted in five major steps. (i) Synthesis of CSS NCs, characterization and study of their structural and photophysical properties (ii) Surface functionalization to investigate the surface ligand chemistry on their optical and electrical properties and to make the NCs compatible for devices and bio-application (iii) Cytotoxicity study and bio-imaging using the Alumina coated NCs. (iv) Optoelectronic characterization, to understand the optical and electronic characteristics of the NCs on film. Finally (v) fabrication of LED using these NCs as an active layer and optimization to achieve an efficient NIR emission.
Original text from CORDIS.
Participants
- TECHNISCHE UNIVERSITAET DRESDEN · DresdenCoordinatorGermany
Links
Data: CORDIS, © European Union