Efficiency Enhancement of Gallium Arsenide Photovoltaics Using Solution-Processed Zinc Oxide Nanoparticle Light Scattering Layers

We demonstrate a high-throughput, solution-based process for subwavelength surface texturing of a III-V compound solar cell. A zinc oxide (ZnO) nanoparticle ink is spray-coated directly on top of a gallium arsenide (GaAs) solar cell. The nanostructured ZnO films have demonstrated antireflection and light scattering properties over the visible/near-infrared (NIR) spectrum. The results show a broadband spectral enhancement of the solar cell external quantum efficiency (EQE), a 16% enhancement of short circuit current, and a 10% increase in photovoltaic efficiency

Semi-Transparent Polymer Solar Cells with Excellent Sub-Bandgap Transmission for Third Generation Photovoltaics

Semi-transparent organic photovoltaics are of interest for a variety of photovoltaic applications, including solar windows and hybrid tandem photovoltaics. The figure shows a photograph of our semi-transparent solar cell, which has a power conversion efficiency of 5.0%, with an above bandgap transmission of 34% and a sub-bandgap transmission of 81%

State of the Art of Microwave Treatment of Wood: Literature Review

This paper presents a survey of the state of the art of microwave (MW) treatment of wood, informed by both past and recent research papers. It begins by introducing the main concepts regarding MW technology and its advantages, presenting a holistic perspective of this technology, and identifying 57 research papers published over the last 25 years. Next, an extensive literature review of the most significant experimental research papers is provided, divided into two MW heating treatment uses: wood drying and permeability improvement. For each study, the wood species, MW parameters, main objectives, and overall conclusions are provided. In this context, an explanation is given on how parameters such as MW power, frequency, intensity, and exposure time, as well as initial moisture content, influence the degree of wood modification. Next, a global overview of the most used wood species, genera, and dimensions is revealed. The paper concludes by indicating the potential fields of future research studies concerning the uses and applications of MW treatment technology

Development of a beam imaging system for the European spallation source tuning dump

To provide essential beam diagnostics for the spallation target and for the tuning dump of the European Spallation Source (ESS) with its high-power, low-emittance proton beam, optical imaging systems have been developed allowing remote viewing of the beam profiles, using scintillation light from coatings on the proton beam window (PBW) at the accelerator exit and the target entry window (TW), and insertable interceptive screens at the tuning dump (TD). In this paper, we present the techniques used and the main parameters in the design of the TD system, including the optical configurations modelled in the software Zemax OpticStudio (ZOS). We also present the design principles for reflective optics which can transmit high-quality images, showing the performance of the imaging systems as predicted by ZOS and by prototyping. We take account of the requirements for initial alignment and ongoing maintenance of the optical system. Studies of the radiation and thermal environments, which impact on sensitive optical components such as cameras and mirrors, are also described, as are mechanical considerations for the vacuum vessels and screen actuators. Finally, comments are made on the applicability of similar optics to diagnostic systems at other neutron sources and accelerators