Science & Technology

NREL, Mining Research May Show How to Make Better Silicon Solar Panels

US Department of Energy Researcher National Institute of Renewable Energy (NREL) and the Colorado School of Mines are applying new technologies to identify defects in silicon solar cells that cause reduced efficiency. Lessons learned at the atomic level can lead to improvements in the way manufacturers enhance their products against what is known as light degradation.

Photoinduced degradation (LID) reduces the efficiency of silicon solar cells by about 2%. This will significantly reduce the output over the 30 to 40 year life of the technology introduced in the field. Silicon solar cells make up more than 96% of the world market, and the most commonly used semiconductors used to make these cells are made of boron-doped silicon. However, boron-doped silicon is susceptible to LID, so manufacturers have developed ways to stabilize solar modules.

Without an understanding of defects at the atomic level, researchers said it was impossible to predict the stability of those modules.

“Some modules are perfectly stable, and some of them are only half-stabilized,” said PhD Abigail Meyer. Mine candidates and NREL researchers. She is the lead author of a new treatise detailing efforts to identify the cause of the LID phenomenon. The article “Atomic Structure of Light-Induced Efficiency Degradation Defects in Boron-doped Czochralski Silicon Solar Cells” is published in the journal Energy & Environmental Science.

Her co-authors are NREL’s Vincenzo La Salvia, William Nemeth, Matthew Page, David Young, Paul Stradins, and Mines’ Sumit Agarwal, Michael Venuti, Serena Eley. Former mine professor P. Craig Taylor consulted on the study.

Stratins, Principal Scientist and Project Leader in Silicon Photovoltaic Research at NREL, has studied the LID problem for decades, but has identified the exact microscopic nature of the cause of degradation. It states that it is not. Through indirect experiments and theory, researchers have concluded that using less boron or less oxygen in silicon reduces the problem.

The collaboration between NREL and mining researchers relied on electron paramagnetic resonance (EPR) to identify the defects responsible for LID. For the first time, microscopic examination revealed clear signs of defects as the sample solar cells were further degraded by light. When scientists applied an empirical “regeneration” process to repair industry-adopted LIDs, the signs of defects disappeared. Surprisingly, researchers also discovered a second “wide” EPR signature affected by exposure, involving far more dopant atoms than LID defects. They hypothesized that not all atomic changes caused by light lead to LID.

Scientists extend the technology developed to study LID to reveal degradation defects in silicon solar cells and other semiconductor materials used in solar power generation, such as cadmium telluride and perovskite. can do.

The Solar Energy Technology Office within the Department of Energy funded the research.

NREL, Mining Research May Show How to Make Better Silicon Solar Panels NREL, Mining Research May Show How to Make Better Silicon Solar Panels

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