Frequently Asked Questions on Cathodoluminescence and More

Yes, we offer full customization of the CL detection, both spectrally resolved and single-channel. Do not hesitate to contact us if your CL experiments require different CL detection than our standard options. It is highly probable that we can meet your request for a custom detector, either at purchase time or as a field upgrade.

Quantitative cathodoluminescence (qCL) is a technique that measures the intensity and spectral characteristics of light emitted from a material when it is excited by an electron beam. It provides detailed, quantitative information about the optical properties, such as bandgap, emission efficiencies, and defect densities, enabling precise analysis of material properties and behaviours.

Cathodoluminescence is widely used to analyse a large variety of materials, including semiconductors, insulators, quantum materials, and materials with specific electronic or optical properties. It is particularly valuable in electronics, photonics, and nanotechnology to investigate emission characteristics, defect structures, and bandgap properties. Additionally, cathodoluminescence is also effective for studying minerals, gems, rare earth elements, organic materials and biological samples. The technique provides detailed insights into the optical, composition and structural properties at both microscopic and nanoscopic levels.

Yes, it is. The Attolight system functions as a standard scanning electron microscope (SEM), allowing you to operate it in the same way you would with any existing SEM.

The Attolight SEM column has been designed to deliver higher probe currents at a slightly decreased resolution, because cathodoluminescence map resolution is generally limited by charge carrier diffusion distance, not probe size. This design choice enables faster data acquisition both in regular and time-resolved CL.

Compared to competitor CL systems, the Allalin and Säntis light collection systems do not require any further alignment once installed and calibrated. The optical collection system is fixed, which guarantees that the results are accurate, repeatable and quantitative.

Yes, the continuous mode Allalin system is upgradable to the time-resolved system. The upgrade involves installing a pulsed laser or beam blanking system and adding a time-resolved detector to the light detection system. This upgrade can be performed on-site by our service engineers.

Yes, the Attolight system can operate in continuous wave cathodoluminescence (CWCL) mode even with the time-resolved system. While the electron beam is pulsed, you can use a continuous detector, such as a photomultiplier or CCD camera to detect the signal.

Time-resolved cathodoluminescence (TRCL) experiments involve studying the emission of light from a material under electron excitation with a time resolution. This technique provides valuable insights into the dynamic processes occurring at the nanoscale or microscale.

Here are some types of information you can obtain from time-resolved cathodoluminescence experiments:

Lifetime of Excited States

Time-resolved CL allows researchers to measure the lifetime of excited electronic states within a material. This information is crucial for understanding the dynamics of charge carriers, such as electrons and holes, in semiconductors and other luminescent materials.

Carrier Diffusion and Transport

By tracking the emission over time, researchers can gain insights into the diffusion and transport of charge carriers within a material. This is particularly important for materials used in electronic and optoelectronic devices.

Recombination Dynamics

Time-resolved cathodoluminescence can reveal information about the recombination processes occurring in a material. It helps in understanding how quickly electrons and holes recombine and emit photons.

Defects and Trap States

Luminescent defects or trap states in a material can affect the lifetime of excited states. Time-resolved CL can provide information about the nature and energy levels of these defects, which is crucial for optimizing material properties.

Energy Transfer Processes

In materials with multiple components or phases, time-resolved CL can help study energy transfer processes between different regions. This is particularly relevant in nanomaterials and composite structures.

Optical Properties Under Dynamic Conditions‍

Time-resolved CL provides a way to investigate how a material's optical properties change over very short time scales. This is important for understanding the response of materials to rapid changes in excitation conditions.

Applications in Nanophotonics‍

TR-CL is useful for studying and optimizing materials for applications in nanophotonic, where the behaviour of light at the nanoscale is crucial.

Characterization of Semiconductor Devices‍

TR-CL is employed in the characterization of semiconductor devices, such as light-emitting diodes (LEDs) and solar cells, to understand and optimize their performance.

By combining time-resolved cathodoluminescence with other imaging and spectroscopic techniques, researchers can obtain a comprehensive understanding of the optical and electronic properties of materials, which is valuable for various scientific and technological applications.

No, Attolight systems are designed to minimize contamination. Our systems are equipped with advanced vacuum and cleanliness protocols to ensure that samples remain uncontaminated during measurements.

Helium usage must be separated between cooling down phase (fixed He quantity) and usage to maintain the baseline cryo-temperature (usage over time). The cryostat consumes approximately 60 Liters of liquid Helium over 4 working days, with each working day consisting of 8 hours of low-temperature (10 K) experimentation.

The Allalin platform offers various options to enhance its functionality and adaptability to different research needs, including:

• Time-resolved mode
• Ultra-low temperature analyses
• Nanoprobes
• In-SEM electrical measurements
• g² autocorrelation measurements 
• In-SEM photoluminescence
• In-SEM Raman spectroscopy

And note that on an existing Allalin platform many others options we can be installed initially or later.

Yes, it does. We have included additional electrical connectors on the vacuum chamber door so that you can easily connect your custom systems.