U.S. Department of Energy - Energy Efficiency and Renewable Energy

SunShot Initiative

High-Performance Nanostructured Coating

Two illustrations side by side showing how sunlight is absorbed through layers on the left, and on the right, blue dots are above rectangular slab with two layers.

Schematic of the proposed spectral selective coating (SSC). The illustration on the left shows how concentrated sunlight is absorbed by the SSC layer on a stainless steel tube to raise the temperature of the heat transfer fluid. On the right, SSC with nanoparticles is embedded in a dielectric matrix.

The University of California San Diego, under the 2012 SunShot Concentrating Solar Power (CSP) R&D funding opportunity announcement (FOA), is developing a new low-cost and scalable process for fabricating spectrally selective coatings (SSCs) to be used in solar absorbers for high-temperature CSP systems.


The research team is working to demonstrate a refractory, nanoparticle-based coating that can achieve an effective solar absorptance greater than 94% and an effective infrared emittance lower than 7% at 750°C. This enables high thermal conversion efficiencies (≥ 90%) and increased temperature ranges for heat-transfer fluids (≥ 650ºC). The goals of this project are to:

  • Fabricate refractory semiconductor nanoparticles, as well as surface-protected semiconductor nanoparticles by scalable synthesis techniques, and then spray-coat them in ambient atmosphere onto an absorber metal surface
  • Model and measure optical and thermal properties, such as solar absorptance and infrared emittance
  • Achieve high-temperature durability by using modified semiconductors, refractory nanoparticles, ceramic matrix nanocomposites, and high-temperature annealing.


This research employs the novel use of surface-protected semiconductor nanoparticles, which are fabricated by a highly scalable particle synthesis method with desired size distributions. By engineering the material properties and morphologies of the nanoparticle coating, the proposed SSCs simultaneously possess the metrics of high performance, low cost, and high-temperature durability.

Publications, Patents, and Awards

At this time, this project does not have published articles, patents, or awards.

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Progress Reports
May 2013

The SunShot CSP R&D program seeks to accelerate progress toward the cost target of $0.06 per kilowatt-hour through novel and revolutionary research into CSP technologies. Learn about other DOE competitive awards for concentrating solar power research that are in progress.