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Accelerated Stress Testing to Deconvolute Simultaneous-But-Distinct Degradation Pathways Under Ultraviolet Illumination

DuraMAT will address simultaneous-but-distinct degradation pathways occurring from ultraviolet (UV) radiation in high-power density bifacial photovoltaic (PV) modules with advanced cell technologies, such as passivated emitter and rear contact (PERC), tunnel-oxide passivated contact, and silicon heterojunction with intrinsic thin layer.

This project will:

  • Assess degradation rates of individual packaging components as well as the combined cell+package system
  • Apply sequential accelerated stress testing with compounding stressors in addition to UV light
  • Perform targeted chemical analysis to assess degradation pathways.

Core Objective

Disruptive Acceleration Science


National Renewable Energy Laboratory (NREL)


  • Degradation rates for various cell architectures and encapsulants will be quantified. These values can be used by others in future degradation models.
  • Signatures for UV-induced degradation will be documented, which can inform future identification of UV effects on photovoltaic modules.
  • Compounding effects of UV exposure in sequence with other stressors (e.g., potential-induced degradation, damp heat, and humidity freeze) will be investigated. This will provide understanding of broader impacts of UV and inform further development of sequential accelerated stress procedures.


Available to NREL scientists and external collaborators.


Sinha, et al. "UV-induced degradation of high-efficiency silicon PV modules with different cell architectures" Progress in Photovoltaics: Research and Applications 2023, 31, 36-51.

Sulas-Kern, et al. "Electrochemical Degradation modes in bifacial silicon photovoltaic modules" Progress in Photovoltaics: Research and Applications 2022, 30, 948-958.

Hacke, et al. "Acceleration Factors for Combined-Accelerated Stress Testing of Photovoltaic Modules" Solar RRL 2023, 7, 2300068.


To learn more about this project, contact Dana Kern and Peter Hacke.

Two rows of six cell images, labeled

Example of a degradation mode to be addressed in this work: A bifacial PERC cell with UV-blocking encapsulant before and after irradiation plus compounding stress characterized by photoluminescence (PL), electroluminescence (EL) at high and low injection, and power loss.