Colloidal Quantum Dot Optoelectronic Applications

Colloidal quantum dots (CQDs) are nanoscale semiconductor crystals synthesised and processed in solution, exhibiting size-tunable bandgaps and strong quantum confinement. These features enable precise control of optical absorption and emission across the visible to infrared spectrum. In optoelectronic applications, CQDs serve as active layers in photodetectors, light-emitting diodes, photovoltaics and lasers, offering low-cost, large-area, and flexible device fabrication. Surface chemistry and core–shell engineering have advanced charge-carrier lifetimes, photoluminescence quantum yields and environmental stability. Integration with photonic structures and ligand exchange strategies further improve light–matter coupling and carrier transport. Recent efforts target short-wave, mid-wave and long-wave infrared photodetection, high-efficiency solar cells, and bioimaging probes. Across applications, enhanced device performance has been achieved through intraband transition engineering, nanoscale device patterning and tailored heterostructure design, underlining the global significance of CQDs for sustainable, scalable optoelectronics.

Research from Nature Portfolio

Recent studies have demonstrated intraband infrared photodetectors based on colloidal mercury chalcogenide nanocrystals. By combining HgSe and HgTe quantum dots, researchers have engineered an artificial quantum-well landscape that yields low dark current, rapid response and large thermal activation energy, achieving the highest reported intraband detection performance in a solution-processed device. Separately, synthesis advances using diffusion-dynamics control in continuous injection processes have enabled the production of highly monodisperse indium arsenide quantum dots exceeding 9 nm in diameter with narrow size distributions. This precise control of monomer flux addresses growth limitations and underpins improved infrared photodetector and photovoltaic performance. In another development, photoconduction at the carrier diffusion-length limit has been realised by lithographically defining sub-micrometre trenches in HgTe nanocrystal films. The resulting devices reach responsivities near 1 kA W⁻¹ and specific detectivities above 10¹² Jones at short-wave infrared wavelengths, setting new benchmarks for nanoscale colloidal infrared sensors.

Colloidal Quantum Dot Optoelectronic Applications publication trend

The graph below shows the total number of articles in colloidal quantum dot optoelectronic applications across all publications each year (not limited to Nature Index journals).

Technical terms

Colloidal quantum dot: A semiconductor nanocrystal synthesised in solution with a size-dependent bandgap.

Quantum confinement: The phenomenon where charge carriers are spatially confined in all three dimensions, altering energy levels.

Intraband transition: Optical absorption or emission involving electronic transitions within the same band (e.g. conduction band).

Core–shell structure: A nanoparticle architecture with a semiconductor core and a different material shell for surface passivation and performance tuning.

Specific detectivity (D*): A figure of merit for photodetectors defined by the signal-to-noise ratio normalised to detector area and bandwidth.

References

1. A colloidal quantum dot infrared photodetector and its use for intraband detection. Nature Communications (2019).
2. Diffusion dynamics controlled colloidal synthesis of highly monodisperse InAs nanocrystals. Nature Communications (2021).
3. Infrared photoconduction at the diffusion length limit in HgTe nanocrystal arrays. Nature Communications (2021).
4. High-operating-temperature mid-infrared photodetectors via quantum dot gradient homojunction. Light: Science & Applications (2023).
5. Colloidal III–V Quantum Dot Photodiodes for Short‐Wave Infrared Photodetection. Advanced Science (2022).
6. Colloidal quantum dots for thermal infrared sensing and imaging. Nano Convergence (2019).