Photovoltaic Advanced Materials and Devices
This is a resonance-coupled photoconductive decay system invented by Dick Ahrenkiel and Steve Johnson to measure minority carrier lifetimes in semiconductor materials. A silicon wafer is being placed in the sample stage.
R&D activities within Advanced Materials and Devices include the following areas:
Materials
Three general technical areas are covered in this area—crystalline silicon, thin films, and modules. Crystalline silicon technology is advancing through research on materials, devices, and processes. Key thin- film technologies include amorphous silicon (a-Si), copper indium diselenide (CIS) and its alloys, cadmium telluride (CdTe), and thin films using a multijunction design. Cells are assembled into PV modules, which are optimized to improve performance beyond present limits.
New concepts
The Solar Program pursues new technologies and concepts that hold potential promise for the future. However, barriers and challenges must be understood and overcome for these technologies to move forward to continue, more intense R&D. We discuss activities within the Beyond the Horizon and Future Generation PV programs, advanced building-integrated concepts, and other advanced solar conversion schemes.
Three programs that contribute to the activities in Advanced Materials and Devices include the following:
A research team led the way with a 16.5%-efficient cadmium telluride (CdTe) PV cell and device structure that surpassed the former world record by 0.7%, absolute.
Thin Film PV Partnership
Primarily a subcontracted program that helps to develop solar cells and modules based on extremely thin layers of both active PV materials and other essential materials such as contacts. Thin films are being developed because of their high potential for low-cost solar cells.
The leading thin-film materials (or technologies) are amorphous silicon, cadmium telluride, copper indium diselenide, and thin-film silicon. A national team for each thin-film technology comprises the nation's best research and engineering talent drawn from industry, universities, and the national laboratories. In addition, a crosscutting national team, begun in 2002, addresses packaging issues of thin-film modules. Key challenges in thin-films research include improving every aspect of active-layer manufacturing to reach low-cost production, improving commercial module efficiencies, and ensuring outdoor reliability of devices and modules.
Crystalline Silicon Module Reliability
Addresses performance, reliability, and testing of crystalline silicon modules. We perform outdoor durability testing and accelerated testing, as well as failure analysis, on modules to determine areas for further R&D and improvement. Modeling supports experimental procedures to help understand and solve reliability issues.
PV Manufacturing R&D
A subcontracted program designed to improve PV manufacturing processes and products. The goals include reducing costs, providing a technology foundation that supports significant manufacturing scale-up, and positioning the U.S. industry to meet rapidly emerging opportunities for large-scale deployment.
Individual manufacturers, building on their own unique approaches, perform the R&D. Projects focus on improvements in the following:
- Module-manufacturing processes to increase module reliability
- System and system-component packaging, system integration, manufacturing, and assembly
- Flexibility of product manufacturing
- Balance-of-systems development, including storage and quality control