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

Solar Energy Technologies Program

Thin Films

Photo of thin-film photovoltaic modules built into roof shingles.

A record-setting new technology is also bringing a new look to the familiar roof-top solar energy system for homes or businesses. With research from NREL, United Solar Systems Corp. has developed thin-film photovoltaic modules that are built right into roofing shingles. This new product helps the triple-junction or three-layered—solar panels blend into the natural contours and overall look of a building. This new technology has brought NREL and the company three national awards, including an R&D 100 award from R&D Magazine.

Thin films of special photovoltaic material can produce solar cells with relatively high conversion efficiencies, while using much less material than crystalline silicon cells. The key materials or technologies that we will discuss are amorphous silicon (a-Si), copper indium diselenide (CIS) and its alloys, and cadmium telluride (CdTe). We also will discuss thin films that use a multijunction design.

Our R&D activities include the following goals:

  • Improve every aspect — for example, rate, yield, capital cost, throughput, materials use — of manufacturing the active layer to reach the low, desired capital investment level. This goal is sought while maintaining all other qualities such as module efficiency.

  • Improve efficiencies of commercial modules to levels above 10% (and incrementally, toward 15%).

  • Ensure the outdoor reliability of intrinsic devices and packaged modules (at low costs). The two main challenges are first, developing stable intrinsic materials and devices, and second, developing robust, yet inexpensive, module packaging.

To learn more about PV materials, see: