Category Archives: Technical

AttoLight’s CHRONOS Time-Resolved Cathodoluminescence for characterizing CIGS SOLAR CELL

Attolight’s Chronos time-resolved cathodoluminescence tool was recently used to characterize an advanced Cu(In,Ga)S2 device that showed an efficiency of 15.2% from a H2S-free, Cd-free, and KCN-free process. significantly limited mainly due to photovoltage (Voc) losses in the bulk and at the interfaces. Here, via a combination of photoluminescence, cathodoluminescence, electrical measurements, and ab initio modeling, we address the bulk and interface losses to improve ∼1.6-eV-band-gap (Eg) Cu(In,Ga)S2. The optoelectronic quality of the absorber improves upon reducing the [Cu]/[Ga+In] (CGI) ratio, as manifested by the suppression of deep defects, higher quasi-Fermi level splitting (QFLS), improved charge-carrier lifetime, and higher Voc. We identify antisite CuIn/CuGa as a major performance-limiting deep defect by comparing the formation energies of various intrinsic defects. Interface recombination is suppressed using a Zn(O,S) buffer layer in Cu-poor devices, which leads to the activation energy of recombination equal to the Eg. We demonstrate an efficiency of 15.2% with Voc of 902 mV from a H2S-free, Cd-free, and KCN-free process.

Context & scale

Cu(In,Ga)S2 is a high-potential material for its usage in tandem solar cells; however, its power conversion efficiency has remained limited so far. High bulk recombination losses and interface losses both account for the performance limitation. In this work, we adopt a holistic approach to address both bulk and interface recombination losses. We show that bulk recombination losses can be substantially suppressed by controlling the Cu deficiency in the material. From theoretical calculations, we argue that Cu deficiency reduces the antisite defects that are probably the most detrimental defects. Additionally, we effectively passivate the interface through the usage of Zn(O,S) buffer layer, thereby minimizing the losses at the interface. This leads to a solar cell device performance of over 15% from 1.6-eV-band-gap Cu(In,Ga)S2 from a completely non-toxic process. The path to further performance improvement is discussed to increase the viability of Cu(In,Ga)S2 toward tandem application.

For More information

View Attolight Page
Visit the Attolight Website

Contact Us Online Form
Phone: 916-897-2441
Email: info@Barnett-Technical.com

Quantum Diamond AFM

Quantum Diamond Atomic Force Microscope (QDAFM) is a quantum precision measurement instrument based on both nitrogen-vacancy (NV) center in diamond and AFM scanning imaging technology. It can be detected with magnetic imaging quantitatively and non-destructively by quantum control and readout of spin in luminous NV center defect. With nanoscale high spatial resolution and single spin ultra-high detection sensitivity, QDAFM is an innovative technology to develop and study area of physics, chemistry, material science, life science, biomedical science, etc, such as high density magnetic storage, spintronics, magnetic domain imaging, 2D materials, topological magnetic structure, superconducting magnetic, cell imaging and quantum techniques applications.

Click here to learn more about this cutting edge technology.

Anisotropic Thermal Conductivity and Diffusivity Measurements of Li-ion Batteries

Li-ion batteries represent many of the most critical areas of development in energy storage.  The appeal of these systems arise from their higher energy densities, longer life cycles (charge and discharge), and lighter weight compared to typical battery chemistries.

To read more about our ground breaking instruments for thermal testing read the following Steve’s Solutions article.

Ramanomics: Quantification of Proteins, Nucleic Acids, and Lipids Inside Eukaryotic Cells

Molecular function in eukaryotic cells can be studied by quantifying proteins, nucleic acids, and lipids inside intracellular organelles. Traditionally, this quantification is performed through techniques that are given “-omic” terms such as proteomics, metabolomics, lipidomics, etc. using mass spectrometry (MS)-based techniques. 

Raman spectroscopy has traditionally been used to quantify the molecular structure of a wide range of chemical species with size ranges from near-field (<100 nm) to bulk measurements. Extensive work has gone into the application of Raman spectroscopy in many biochemical applications but successful solutions have often been difficult due to the complexity of the information obtained in the measurement and interferences arising from the laser-based methods used for Raman spectroscopy. Dr. Andrey Kuzmin of the University at Buffalo and Advanced Cytometry Instrumentation Systems, LLC, has successfully bridged this gap with the application of Raman spectroscopy to the quantification of intracellular components.  His development, termed “Ramanomics” can be used to quantify proteins, DNA, RNA, and lipids in live cells.

Click here to read the entire article.

Installation Highlights

We are glad to share the news about the implementation of Barnett Technical Services installation of a significant engineering project.

The company has received the request and later an order from the Chevron energy corporation’s research center to develop an IR Fourier Spectrometer for controlling the chemical reaction in the on-line process.

The Barnet Technical Services Team along with Ostec engineers have implemented developing the industrial version on the basis of the standard air based FTIR spectrometer IROS 05. To transform the research device into an industrial unit it was necessary to develop a sealed device case filled with dry nitrogen under extra pressure, to select and replace a typical IR detector with an MCT detector with Peltier cooling, to develop a cooling system and temperature stabilization for ensure the lowest possible noise level inside the device, as well as specialized software for obtaining data and its subsequent processing.

Microplastics Isolation and Characterization

Microplastics contaminate marine, freshwater and terrestrial ecosystems around the world. The growing prevalence of these contaminants requires study on their impact on human health and ways in which they can be identified and remediated.

Barnett Technical Services (BTS) has participated in a study set up by the State of California to assess methods for counting and characterizing micro plastic particles in water. This summary illustrates some of the methods BTS used in this study.

Click here to read the entire article.

Failure analysis and particle isolation in a post-COVID-19 world.

The spread of COVID-19 has led to great changes in the lives of people worldwide.  This includes the need for increased social distancing and the use of Personal Protective Equipment (PPE) to minimize the risk of spreading and acquiring disease from others and the surrounding environment. The use of PPE, including gloves, safety goggles, and a mask causes difficulties for failure analysis and particle isolation where precise microscopic sample handling is often required.  Precise manipulations using probes and other handheld tools while looking through a microscope, are much more difficult while wearing PPE.

The Micro Support Axis Pro micromanipulator is an excellent solution for performing precise microscopic sampling where PPE is required.  

Click here to read the entire article.