The cost of photovoltaic (PV) modules has declined by 85% since 2010. To achieve this reduction, manufacturers altered module designs and bill of materials; changes that could affect module durability and reliability. To determine if these changes have affected module durability, we measured the performance degradation of 834 fielded PV modules representing 13 module types from 7 manufacturers in 3 climates over 5 years. Degradation rates (Rd) are highly nonlinear over time, and seasonal variations

Articles you may be interested inSingle-mode quantum cascade lasers employing asymmetric Mach-Zehnder interferometer type cavities Combining the recent progress in semiconductor nanostructures along with the versatility of photonic crystals in confining and manipulating light, quantum networks allow for the prospect of an integrated and low power quantum technology. Within quantum networks, which consist of a system of waveguides and nanocavities with embedded quantum dots, it has been demonstrated in theory that many-qubit states stored in electron spins could be teleported from one quantum dot to another via a single photon using the single-photon Faraday effect. However, in addition to being able to transfer quantum information from one location to another, quantum networks need added functionality such as ͑1͒ controlling the flow of the quantum information and ͑2͒ performing specific operations on qubits that can be easily integrated. In this paper, we show how a single-photon Mach-Zehnder interferometer ͑SMZI͒, that uses the concept of the single-photon Faraday effect to manipulate the polarization of a single photon, can be operated both as a switch to control the flow of quantum information inside the quantum network and as various single-qubit quantum gates to perform operations on a single photon. Given that the X gate, the Z gate, and the XZ gate are essential for the implementation of quantum teleportation, we show explicitly their implementation by means of our proposed SMZI. We also present the implementation of the Hadamard gate and the single-qubit phase gate, which are needed to complete the universal set of quantum gates for integrated quantum computing in a quantum network. Finally, the expected fidelity and robustness of the proposed SMZI are quantitatively explored by considering the phase errors within the SMZI.

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This article is the third and final article in a series dedicated to reviewing each process step in crystalline silicon (c-Si) photovoltaic (PV) module manufacturing process: feedstock, crystallization and wafering, cell fabrication, and module manufacturing. The goal of these papers is to identify relevant metrology techniques that can be utilized to improve the quality and durability of the final product. The focus of this article is on the module manufacturing process. The c-Si PV module fabrication process can be divided into three primary areas; (1) stringing and tabbing, (2) lamination, and (3) integration of junction box and bypass diode(s). Each of these processing steps can impact the reliability and durability of PV modules in the field. The ultimate goal of this article is to identify appropriate metrology techniques and characterization methods that can be utilized within a module manufacturing facility to improve the reliability and durability of the final product. Additionally, a gap analysis is carried out to identify areas in need of further research and a discussion is provided that addresses new challenges for advanced materials and emerging technologies.

This article is the second article in a three-part series dedicated to reviewing each process step in crystalline silicon (c-Si) photovoltaic (PV) module manufacturing process: feedstock and wafering, cell fabrication, and module manufacturing. The goal of these papers is to identify relevant metrology techniques that can be utilized to improve the quality and durability of the final product. The focus of this article is on the cell fabrication process. In this review, the fabrication of c-Si PV cells is divided into four steps: (1) wet chemical processes; (2) emitter formation; (3) anti-reflection coating (ARC) and passivation deposition; and (4) metallization. Each of these processing steps can impact the final reliability and durability of PV modules deployed in the field, and here the failure modes and degradation mechanisms induced during cell manufacturing are explored. Additionally, a literature review of relevant measurement techniques aimed at reducing or eliminating the probability of such failures occurring is presented along with an assessment of potential gaps wherein the PV community could benefit from new research and demonstration efforts.

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This article is the first in a three-part series of manufacturing metrology for c-Si photovoltaic (PV) module reliability and durability. Here in Part 1 we focus on the three primary process steps for making silicon substrates for PV cells: (1) feedstock production; (2) ingot and brick production; and (3) wafer production. Each of these steps can affect the final reliability/durability of PV modules in the field with manufacturing metrology potentially playing a significant role. This article provides a comprehensive overview of historical and current processes in each of these three steps, followed by a discussion of associated reliability challenges and metrology strategies that can be employed for increased reliability and durability in resultant modules. Gaps in the current state of understanding in connective metrology data during processing to reliability/durability in the field are then identified along with suggested improvements that should be considered by the PV community.