Electron Microscopy Laboratory – NANO

Print Friendly

Electron Microscopy Laboratory – NANO

Laboratory of Electron Microscopy fitted with modern equipment, provides services in the area of specialized mineralogical and metallographic analyses, and expertise in the scope of observation and verification of processes. The Laboratory performs research projects and commercial orders.

  • Automatic SEM analysis and identification of minerals
  • Composition, phase and structure analysis at various size scale of materials including particles, deposits, dusts and soils.
  • Evaluation of structure in terms of grain distribution, precipitates, inclusions and porosity
  • In-situ SEM observation of transformations upon sample heating up to 1400 °C
  • Imaging of semi-liquid and oily materials in SEM environmental mode
  • 3D imaging of structure and 3D mapping of composition
  • Composition and structure analysis of additives in composite and ceramic materials (e.g. polymer composites and construction ceramics)
  • Characterization of post-production materials and semi-finished products
  • Verification of technological processes (e.g. quality of chemical etching, surface and structure evolution upon successive treatments)
  • Patterning of submicron structures and fabrication of mechanical (MEMS) and opto-mechanical components (MOEMS)

SEM/FIB MICROSCOPE – FEI HELIOS NANOLAB 450HP

Helios Scanning microscope with electron and ion columns, equipped with EDS detector. It allows general and high-resolution imaging, elemental analysis, three-dimensional data acquisition, and advanced FIB sample preparation for transmission electron microscopy.

TEM MICROSCOPE – FEI TECNAI G2 X-TWIN

TecnaiTransmission electron microscope with LaB6 gun for regular investigation of microstructure and its components with resolution of less than 0.25 nm. The instrument is fitted with EDS spectrometer for elemental analysis.

HR-TEM MICROSCOPE – FEI TITAN3 G2 60-300

TitanDouble CS-corrected transmission electron microscope with high-brightness gun and high-sensitive EDS system for ultra high-resolution structure examination and elemental analysis at the atomic level. The instrument is equipped with X-FEG gun, monochromator, two spherical aberration correctors (probe and image), four EDS detectors (ChemiSTEM), and operates at one of four accelerating voltages, i.e. 300, 200, 80 or 60 kV. It also allows 3D imaging with automated acquisition of tomography tilt series.

The laboratory also includes more than 20 devices and accessories for conventional sample preparation for light, scanning and transmission microscopies.

LME_Team

Head of Laboratory – Alicja Bachmatiuk, PhD, email: Alicja.Bachmatiuk@eitplus.pl,
tel. +48 71 734 71 66

Senior Scientist – Sebastian Arabasz, PhD, email: Sebastian.Arabasz@eitplus.pl, tel. +48 71 734 71 88

Process Engineer – Anna Siudzińska, MSc, email: Anna.Siudzinska@eitplus.pl,
tel. +48 71 734 71 17

Senior Scientist – Sandeep M. Gorantla, PhD, email: Sandeep.Gorantla@eitplus.pl,
tel. +48 71 734 72 99

Contact:

Sales  Department

Aleksandra Borek

mobile.: +48 510 131 925

tel: +48 71 734 72 03

email: aleksandra.borek@eitplus.pl

POLONEZ 1 Research Grant

National Science Centre, Poland                        

Research Fellow: Dr. Sandeep M. Gorantla
 “Atomic scale study of emerging UV-light LEDs by advanced transmission electron microscopy”

Fundamental research in microstructural investigation and understanding of  emerging p-n-junction AlxGa1-xN based ultra-violet light (UV-light) light emitting diodes (LEDs) by advanced atomic resolution Transmission Electron Microscopy (TEM) to contribute to knowledge generation necessary to improve their efficiency.

POLONEZ 1 Research Grant

National Science Centre, Poland                        

Research Fellow: Dr. Sandeep M. Gorantla
 
 

 

 

 

 

“Atomic scale study of emerging UV-light LEDs by advanced transmission electron microscopy”

Fundamental research in microstructural investigation and understanding of  emerging p-n-junction AlxGa1-xN based ultra-violet light (UV-light) light emitting diodes (LEDs) by advanced atomic resolution Transmission Electron Microscopy (TEM) to contribute to knowledge generation necessary to improve their efficiency.

The UV-light emitting regions in a typical UV-LED are known as quantum wells. They are the heart of a UV-LED and are just few nanometers (2-3 nm) in thickness. To study such layers aberration corrected S/TEM is the most appropriate choice as it enables to resolve distances of ~ 80 pm and so typical inter atomic spacing of atoms in matter can be analytically characterized.

 About the project

The main objective of this project is to conduct advanced analytical Scanning/Transmission electron microscopy (S/TEM) studies on novel UV-LED devices related structures using the state-of-the-art double Cs aberration corrected FEI Titan3 G2 60-300  TEM in the host institute EIT+ Wrocław Research Centre, Poland.

To achieve the fundamental understanding of these LEDs; firstly pre-LED structures will be synthesized and studied. This will further lead to synthesis of three different full device structures on which full-scale device TEM characterization studies will be performed. The basic scheme of this project strategy is as shown below:

 Simplified schematic of the full device (D) UV-LED structures that are aimed to synthesize and study in this project are as shown below

 

 By advanced analytical S/TEM studies, the main microstructural aspects that will be the focus of study in this project will be

  • The effect of Mg-dopant atoms on the microstructure of the p-type layers of the UV-LED device structures.
  • Inclusion of novel p-type dopant atoms will be investigated.
  • Combination different epitaxial thin-film growth approaches for n-side and p-side ayers of the full LED structure will be studied.
  • Study of the interfaces to understand the defects, microstructural orientational relations at the interfaces and measure thickness of different thin film layers in a UV-LED structure.
  • Study of dislocations, particularly the threading dislocation originating from sspphire substrate and propagating into as grown layers, other microstructural defects and strain in the thin film layers.

 In addition, other relevant characterization techniques such as X-ray Diffraction (XRD), Atomic Force Microscopy (AFM) will be carried in collaboration with other networking partners in the host institute.

In this project, the study will cover all the critical microstructure aspects AlxGa1-xN based UV-LEDs that will enable transferring of the knowledge generated in this project to optimizing the fabrication protocols to improve their currently limited efficiencies.

Background

A UV-LED is a semiconductor light emitting diode which emits lights in the ultraviolet light wavelengths of typically 200 – 400 nm. It is a p- n junction diode to which when electric voltage is applied, electrons recombine with holes, in the active region between p and n layers of the device, and it emits photons (light) through the physical phenomenon of electroluminescence.

Now-a-days it is very apparent that the advancements in solid-state lighting technologies based on LEDs is rapidly transforming the landscape of traditional models of lighting sources. This is evident over a broad spectrum of different realms of the society, from the light bulbs in our homes, outdoor lighting, automotive lighting, to the medical surgery theatres. Besides, LED lighting technologies have further expanded into emitting wavelengths shorter than visible light enabling the feasibility of UV-light LEDs. The emission in shorter wavelength range of 100-280 nm is known as UV-C range. The UV-light radiation with wavelengths of  254 nm or less have disinfecting properties as they are effective in killing bacteria, viruses and other microbes. It is owing to this fact that UV-LEDs hold the promise to replace the currently used mercury lamp UV-light sources as potential candidates for water purification applications. The succession of these conventional mercury lamp UV- light sources with UV-LEDs is highly desired. This is because LEDs sources are more environmentally friendly (non-toxic and low energy dependency), cost-effective, compact, and robust.

At present the practically achievable external quantum efficiency (EQE) of AlxGa1-xN UV-LEDs is in the range 1-2 %. This is much lower than the efficiency of commercially available alternative UV-light sources in the market.The factors (e.g. defects, Mg dopant atom clustering, lattice strain) responsible for limiting their efficiency are known but not yet fully understood at their microstructural level. This fundamental research aims to contribute to the desired further improvement of the UV-LEDs which are at present in their early phase of development.

Cooperation

The project will be carried in cooperation with the host institute collaborating partner Dr. Alicja Bachmatiuk and synthesis of the structures will be performed in collaboration with Prof. Detlef Hommel and his research group at EIT+. Other networking partners are Prof. Anette E. Gunnaes, University of Oslo, Norway.

Financing

This research grant is funded by National Science Centre, Poland through POLONEZ 1 research fellowship funding scheme for 24 months (01’2017 – 12’2018). The registration number of the fellowship is 2015/19/P/ST5/03802.  This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 665778.

Posted by abachmatiuk, Posted on 08.10.2015
plusfontminusfontreloadfont