DELMIC Microscopy Blog

How to perform lifetime imaging using time-resolved cathodoluminescence?

Posted by Delmic on Mar 12, 2020 2:00:00 PM

What is time-resolved cathodoluminescence? How can performing lifetime mapping or a g(2) mapping add value to your research? In the video below Toon Coenen, product manager at Delmic, gives an explanation of this imaging technique and its applications.

What are the optimal imaging conditions for cathodoluminescence?

Posted by Delmic on Feb 26, 2020 10:43:00 AM

Understanding the effects of the SEM parameters on generating (incoherent) cathodoluminescence(CL) is essential for obtaining high quality CL intensity maps and spectra from various materials. The spatial extent of the electron beam is particularly important when one is seeking to study particular features in a material. So how can you set up optimal imaging conditions for your experiments?

How can cathodoluminescence imaging modes enhance your research in 6 ways?

Posted by Delmic on Feb 19, 2020 12:30:00 AM

Cathodoluminescence is a great tool for obtaining valuable information about the properties of a sample, which can empower researchers and developers with a better understanding of possible defects, efficiency of the material and other properties.

The SPARC cathodoluminescence detector has 6 imaging modes which can enhance your research and provide you with an important information about your samples. Keep reading if you would like to know what exactly the SPARC can benefit your research!

What is the difference between cathodoluminescence and other SEM techniques?

Posted by Delmic on Jan 9, 2020 12:45:00 PM

What are the most common SEM techniques for studying materials?
What kind of data can you get with these techniques?
What makes cathodoluminescence (CL) different from other SEM techniques?
5 advantages of CL imaging

How does cathodoluminescence for measuring photovoltaic materials work?

Posted by Delmic on Dec 10, 2019 1:30:00 PM

Are you interested in the possibilities of cathodoluminescence (CL) for photovoltaics (PV)? Are you eager to figure out how CL imaging works to measure and analyze thin-film solar cells and and other photovoltaic materials? For those who didn’t manage to join the webinar Cathodoluminescence for photovoltaics last month, the recording of this webinar is now available for you!

Sample preparation for cathodoluminescence imaging

Posted by Delmic on Nov 19, 2019 10:30:00 AM

Cathodoluminescence is a specific form of luminescence caused by‘free’ electrons(or simply electron propagating through space). Cathodoluminescence can be generated in the material when an electron beam interacts with it. The technique has proven to be a probeless and contactless inspection with a broad spectral range.

But what are the necessary preparation steps that are needed to perform cathodoluminescence imaging? The sample preparation procedure is not difficult. Here are the steps that you would need to take.

Imaging biological specimens with correlative cathodoluminescence electron microscopy

Posted by Delmic on Oct 14, 2019 3:00:00 PM

Understanding of relationships between structure and function in biological specimen strongly depends on the imaging method. Achieving the proper balance between luminescence and high contrast to simultaneously study specific proteins but also to acquire ultrastructural information is one of the challenges of bioimaging.

Correlative light and electron microscopy (CLEM) is an imaging technique for optoelectronic investigation of structure-function relationships at the nanoscale, which has gained importance in recent years. However, the strong mismatch between optical and electron imaging resolutions is still a limiting factor for CLEM.

Best microscopy techniques for studying CIGS thin-film solar cells

Posted by Delmic on Sep 23, 2019 2:48:00 PM

A copper indium gallium selenide (or CIGS), a direct bandgap semiconductor is being commonly used for solar cell production. Thin-film solar cells made with this structure have received a lot of attention from the photovoltaics community for exhibiting conversion efficiencies of almost up to 23%.

Various microscopy techniques are commonly used to perform optoelectronic characterization of these highly relevant solar cell devices. These techniques include FIB-SEM investigations, for instance, which can help to investigate the high capability solar cells and do the material microstructure measurements. It is also quite common to use such techniques as electron backscatter diffraction, energy-dispersive X-ray spectrometry (EDX), electron-beam-induced current (EBIC).

One extremely powerful technique for analysing Cu(In,Ga)Se₂ layers in high-efficiency solar cells is cathodoluminescence (CL). It is particularly useful for observing the Ga/In gradient and how it influences the optoelectronic properties of Cu(In,Ga)Se₂ layers. It is possible to use energy-dispersive X-ray spectrometry to observe local-band-gap energies, but cathodoluminescence can be a more efficient technique for direct access of these local optoelectronic quantities.

Figure 1: SEM (a) and panchromatic CL images (b) acquired on the same identical area on a cross-section specimen prepared from a ZnO/CdS Cu(In,Ga)Se₂/Mo/glass solar cell stack.

ZnO/CdS Cu(In,Ga)Se₂/Mo/glass solar cell stack (Figure 1) was analysed with cathodoluminescence imaging at room temperature, and a CL spectrum was acquired in each pixel. While comparing the SEM and panchromatic CL images acquired on the same identical area it is possible to see that the CL intensity in neighbouring grains is different. These images also allow to conclude that the intensity is reduced at the grain boundaries due to enhanced nonradiative recombination.

Moreover, peak shifts in the CL map reveal the distribution of the local band-gap energy/wavelength well.

This experiment was performed by a research group from Helmholtz-Zentrum Berlin, which soon will host a workshop dedicated to studying photovoltaic materials with cathodoluminescence. The workshop will consist of several talks and hands-on sessions which will focus on the most relevant and advanced techniques for studying photovoltaic materials. The workshop is free and you can still register for it below.

Best practice for studying plasmonic structures with microscopy

Posted by Delmic on Aug 8, 2019 2:03:39 PM

Plasmons have gained a lot of interest for their ability to strongly confine light to very small volumes, which makes the field of plasmonics so attractive. Various materials can be used in plasmonics, such as aluminium, gold, gallium, and others. One of the main advantages of plasmonic materials is their ability to enhance and direct emission, therefore, they can be successfully used for nanoantennas, sensing and local heating.

Measuring time dynamics with time-resolved cathodoluminescence

Posted by Delmic on Jul 17, 2019 10:37:00 AM

Cathodoluminescence has established itself as a powerful technique for measuring and understanding various properties of light. In the previous blog posts, we explained how intensity mapping can be used to measure amplitude of the electromagnetic waves, hyperspectral CL for wavelength measurements, angle-resolved CL for wave vector, and polarimetry for polarization. These properties of light are not static, which means that there is time dynamics associated with light, which can also be studied. How? Keep reading!