In this paper the theory of mismatch factor of the terrestrial solar spectrum is extended to more accurately represent the irradiance available to specific types of photovoltaic (PV) materials from surface albedo. Using spectra derived from the SBDART radiative transfer model, the effects of a spectrally responsive albedo are illustrated by the differences between the spectrally weighted albedo of hydrogenated amorphous silicon (a-Si:H) and crystalline silicon (c-Si)-based PV technology compa...
Despite being an extremely active area for patent applications, nanotechnology development is being impaired by current intellectual property law. In contrast to other emerging fields at their times, nanotechnology was born as the Bayh–Dole Act enabled universities to lock down fundamental research effectively preventing open competition. Both technical complexity and bureaucratic mishandling of nanotechnology patent applications have created a dense patent thicket of overlapping claims and...
The growth of desktop 3-D printers is driving an interest in recycled 3-D printer filament to reduce costs of distributed production. Life cycle analysis studies were performed on the recycling of high density polyethylene into filament suitable for additive layer manufacturing with 3-D printers. The conventional centralized recycling system for high population density and low population density rural locations was compared to the proposed in home, distributed recycling system. This system wo...
The recent development of the RepRap, an open-source self-replicating rapid prototyper, has made 3-D polymer-based printers readily available to the public at low costs (
Previous work has shown that high-temperature short-term spike thermal annealing of hydrogenated amorphous silicon (a-Si:H) photovoltaic thermal (PVT) systems results in higher electrical energy output. The relationship between temperature and performance of a-Si:H PVT is not simple as high temperatures during thermal annealing improves the immediate electrical performance following an anneal, but during the anneal it creates a marked drop in electrical performance. In addition, the power gen...
Band gap engineering provides an opportunity to not only provide higher overall conversion efficiencies of the reference AM1.5 spectra but also customize PV device design for specific geographic locations and microenvironments based on atmospheric conditions characteristic to that particular location. Indium gallium nitride and other PV materials offer the opportunity for limited bandgap engineering to match spectra. The effects of atmospheric conditions such as aerosols, cloud cover, water v...
An unintended consequence of using “research expenditures” as a figure of merit for universities is to reduce the research output per dollar invested by discouraging the diffusion of superior, lower-cost, open-source scientific equipment.
e inconsistencies associated with the common simple method of evaluating the quality and stability of hydrogenated amorphous silicon (a-Si:H) materials for solar cell applications from just the magnitude of subgap absorption (a(E)) are addressed in this study. The approach taken in this study is to characterize the entire a(E) spectrum by its derivatives, d[a(E)]/dE. Results are presented and discussed for two a-Si:H thin film materials differing in deposition rate by an order of magnitude, w...
Se diseñó y construyó un prototipo funcional de un sistema de medición de radiación solar (global y difusa) basado en un espectrómetro de amplio espectro (UVA, VIS y parte del IR cercano) para el monitoreo solar en Cochabamba, Bolivia, conjuntamente con un sistema similar instalado en Ontario, Canadá. Los datos obtenidos en dos regiones con características geográficas muy distintas ayudaran en el estudio y optimización de materiales fotovoltaicos, para su implementación en diferent...
The use of lasers to weld polymer sheets provides a means of highly-adaptive and custom additive manufacturing for a wide array of industrial, medical, and end user/consumer applications. This paper provides an open source design for a laser polymer welding system, which can be fabricated with low-cost fused filament fabrication and off-the-shelf mechanical and electrical parts. The system is controlled with free and open source software and firmware. The operation of the machine is validated...
With the maturation of digital manufacturing technologies like 3-D printing, a new paradigm is emerging of distributed manufacturing in both scientific equipment and consumer goods. Hardware released under free licenses is known as free and open source hardware (FOSH). The availability of these FOSH designs has a large value to those with access to digital manufacturing methods and particularly for scientists with needs for highly-customized low-volume production products. It is challenging t...
A novel and simple chemical method based on sol-gel processing was proposed to deposit metastable orthorhombic tin oxide (SnOx) thin films on glass substrates at room temperature. The resultant samples are labeled according to the solvents used: ethanol (SnO-EtOH), isopropanol (SnO-IPA) and methanol (SnO-MeOH). The variations in the structural, morphological and optical properties of the thin films deposited using different solvents were characterized by X-ray diffraction, atomic force micros...
This paper describes a simple, low-temperature and cost effective chemical precipitation method in aqueous media to synthesis uniformly distributed zinc oxide (ZnO) microstructures for the fabrication of dye-sensitized solar cells (DSSCs). The size and morphology of the ZnO microstructures are systematically controlled by adjusting the concentration of the precursors, zinc acetate dihydrate and ammonium hydroxide. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used for the...
This study investigates ultra-thin transparent conducting oxides (TCO) of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO) and zinc oxide (ZnO) to determine their viability as candidate materials for use in plasmonic-enhanced thin-film amorphous silicon solar photovoltaic (PV) devices. First a sensitivity analysis of the optical absorption for the intrinsic layer of a nano-disk patterned thin-film amorphous silicon-based solar cell as a function of TCO thickness (10–50 nm) was perfor...
This study provides an in-depth investigation into low-cost and no-cost substrate release mechanisms that allow gas metal arc weld 3-D printed ER4043 aluminum and ER70S-6 steel parts to be removed from a reusable print substrate with minimal energy. Aluminum oxide, boron nitride, and titanium nitride coatings were evaluated as possible substrate release agents for aluminum printing. Additionally, the in situ formation of substrate release agents such as intermetallics and oxides were tested f...