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Search Publications by: Xiaohong Gu (Fed)

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Displaying 1 - 25 of 139

A Spatially-Resolved Evaluation of Accelerated Environmental Aging on Emerging Polypropylene-based Photovoltaic Backsheets using Raman Spectroscopy

March 13, 2025
Author(s)
Ashlee Aiello, Stefan Mitterhofer, Jan Obrzut, Karissa Jensen, Patryk Wasik, Chiara Barretta, Gernot Oreski, Stephanie Watson, Li Piin Sung, Xiaohong Gu
Accelerated aging was used to assess environmental degradation in emerging co-extruded polypropylene (PP)-based backsheets under three different environmental conditions (65 °C/20 % relative humidity (RH), 75 °C/20 % RH, and 75 °C/50 % RH). Although

PVDF-based Backsheet Cracking: Mapping In Situ Phase Evolution by X-ray Scattering

December 15, 2024
Author(s)
Stephanie Moffitt, Sona Ulicna, Song-Syun Jhang, Po-Chang Pan, Michael Owen-Bellini, Peter Hacke, Michael Kempe, Jared Tracy, Kaushik Choudhury, Laura Schelhas, Xiaohong Gu
One of the most common polymers in commercial photovoltaic (PV) backsheets is polyvinylidene fluoride (PVDF). However, recent reports have shown the potential for PVDF-based backsheets to crack and fail prematurely. Previous work has suggested that polymer

Surface photooxidation of polypropylene-based photovoltaic backsheets: A comprehensive spectroscopic investigation

December 8, 2024
Author(s)
Karissa Jensen, Ashlee Aiello, Stefan Mitterhofer, Chiara Barretta, Gernot Oreski, Christopher Stafford, Xiaohong Gu
The prospect of cost reduction, enhanced performance, and improved sustainability has been driving innovation in the development of new backsheet materials for photovoltaic (PV) modules in recent years. Among the materials of interest, polypropylene (PP)

Microstructure changes during failure of PVDF-based photovoltaic backsheets

July 21, 2022
Author(s)
Stephanie Moffitt, Po-Chang Pan, Lakesha Perry, Michael Kempe, Jared Tracy, Kaushik Choudhury, Xiaohong Gu
The backsheet layer of a solar module provides a safety and environmental barrier to the high voltages running through the photovoltaic (PV) cells and electrical contacts within the core of the module. However, in the past decade, backsheet cracking has

Study of Photodegradation of Epoxy Polymer by Using Slow Positron Annihilation Spectroscopy

October 12, 2021
Author(s)
R Zhang, Xiaohong Gu, H Chen, J Zhang, Y Li, Tinh Nguyen, T C. Sandreczki, Y C. Jean
Slow positron annihilation spectroscopy (SPAS) has been used to study the early stage of epoxy photodegradation. Spin-coated samples of a crosslinked epoxy were prepared by stoichiometrically mixing a diglycidyl ether of bisphenol A epoxy resin with 1,3

Graphene oxide/waterborne polyurethane nanocoatings: Effects of graphene oxide content on performance properties

January 15, 2020
Author(s)
David G. Goodwin, Coralie Bernard, Xiaohong Gu, Mat Celina, Marc R. Nyden, Deborah S. Jacobs, Li Piin Sung, Tinh Nguyen
Graphene oxide (GO) is a good nanofiller candidate for waterborne coatings because of its outstanding physical and mechanical properties, good dispersibility in water, and low cost. Here, we report on the performance of a one-part, water-borne polyurethane

Differential degradation patterns of photovoltaic backsheets at the array level

February 4, 2018
Author(s)
Andrew W. Fairbrother, Matthew Boyd, Yadong Lyu, Julien Avenet, Peter Illich, Michael Kempe, Brian P. Dougherty, Laura Bruckman, Xiaohong Gu
Photovoltaic backsheet degradation is commonly related to end-of-life failure of a module, and as such is an important factor in system reliability and longevity. Some module manufacturers have recently begun utilizing non-fluoropolymer-based backsheets in

Interlaboratory study towards a climate-specific test: spectroscopic characterizations of EVA in glass/EVA/glass systems

February 23, 2016
Author(s)
Jae Hyun Kim, Christopher M. Stafford, Yadong Lyu, Li C. Yu, Chiao-Chi Lin, Tinh Nguyen, Xiaohong Gu
EVA as an encapsulant material is exposed to various UV irradiation, thermal cycles, and humidity conditions. Degradation of EVA can reduce not only power generation due to yellowing, but also a structural integrity of a PV module. In order to investigate