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.
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.
Nikon Metrology is partnering with LIG Nanowise to bring super-resolution microscopy using the LIG Nanowise microsphere technology to the Nikon LV100ND and LV150N microscopes. This product (called the LV-Mod) will allow Nikon LV microscopes to achieve spatial resolutions under 100 nm!
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.
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.
Barnett Technical Services has entered the FedEx Small Business Grant Contest. To see our entry page, and to vote for us, please click the FedEx BTS Entry Page Link. You can vote every 24 hours until March 24th (the end of the voting period).
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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.
Advanced Technisales is now a representative of Barnett Technical Services for Ostec and Micro Support products in the Eastern United States. Founded in 2009 Advanced Technisales specializes in selling process optimization and control equipment for R&D, pilot plant and plant. At present we sell in-situ MIR, NIR, Raman, THz-Raman and Particle Size Analysis. We also sell Calorimeters, Automated Lab Reactors and process enhancement software.
The worlds most powerful benchtop optical microscope can now be used with oil immersion or dry air objectives. The new SMAL AIR lens provides up to 240x magnification in full color without the need for water- or oil-immersion techniques.