NREL findings might delay silicon solar panel destruction

• Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) as well as Colorado School of Mines are applying a new technique to recognize defects in silicon solar cells that cause a drop in performance.

The lessons learned at the atomic degree could result in improvements in the method suppliers strengthen their products versus what is called light-induced deterioration.

Light-induced deterioration, or LID, shaves the efficiency of silicon solar cells by around 2%, which amounts to a substantial drop in power result over the 30- to 40-year life-span of the technology deployed in the field. Solar cells made from silicon represent more than 96% of the worldwide market and also one of the most generally utilized semiconductor used in these cells is made from boron-doped silicon. However boron-doped silicon is at risk to LID, so makers have actually established approaches to maintain the solar modules.

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

"Several of the modules are maintained completely. A few of them are just half-stabilized," stated Abigail Meyer, a Ph.D. prospect at Mines and a scientist at NREL. She is the lead writer of a new paper describing initiatives to determine the resource of the LID phenomenon. The article, "Atomic Structure of Light-Induced Efficiency-Degrading Defect in Boron-Doped Czochralski Silicon Solar Cells," appears in the journal Energy & Environmental Science.

Her co-authors are Vincenzo LaSalvia, William Nemeth, Matthew Page, David Young, Paul Stradins, all from NREL; Sumit Agarwal, Michael Venuti, as well as Serena Eley, that are from Mines; and P. Craig Taylor, a retired Mines teacher that consulted on the study.

Stradins, a major researcher as well as a project leader in silicon photovoltaic research at NREL, claimed the problem of LID has been researched for decades but the exact microscopic nature of what creates the deterioration has not been identified. Scientists have ended, through indirect testing and also theory, that the trouble lowers when less boron is utilized or when less oxygen is present in the silicon.

The collaboration in between NREL and Mines scientists count on electron paramagnetic resonance (EPR) to determine defects in charge of the LID. For the first time, the microscopic exam disclosed a distinctive defect signature as the example solar cells ended up being extra broken down by light.

The defect trademark vanished when the scientists applied the "regeneration" procedure to treat the LID that the industry has actually taken on. To their shock, the researchers likewise found a second, "broad" EPR trademark impacted by light direct exposure, entailing much more dopant atoms than there are LID defects. They assumed that not all atomic adjustments generated by light cause the LID.

The methods developed to research LID can be reached reveal other sorts of derogatory defects in silicon solar cells and also in various other semiconductor products made use of in photovoltaics including cadmium telluride and also perovskites, the researchers kept in mind. The Solar Energy Technologies Office within the Department of Energy-funded the research study.