OVERVIEW

Today, silicon remains the most heavily-researched and understood material system in the world; it is non-toxic, abundant, and ideal for use in photovoltaic power generation.

However, present-day c-Si solar materials, while high in energy conversion efficiency, involve silicon production processes (Figure 1) that are complex, wasteful, energy-intense, and not optimized for large-area applications like solar panels.

Figure 1 | Typical Crystalline Silicon Wafer Production - costly and inefficient

Ampulse’s c-Si thin-film, a revolutionary thin-film PV technology, optimizes c-Si energy conversion efficiency while lowering manufacturing costs dramatically in comparison to existing silicon wafer-based technologies. Leveraging patented technologies, processes, and material expertise developed at ORNL and NREL, Ampulse’s c-Si thin-film technology takes advantage of HW-CVD techniques to directly deposit a very thin layer of c-Si onto a uniquely-textured and flexible metal substrate (Figure 2). The HW-CVD process for creating heteroepitaxial silicon minimizes energy input, and eliminates several material-wasting steps, resulting in lower overall module cost.

Figure 2 | Ampulse c-Si Thin-Film Process - eliminates wasteful wafer process

The Ampulse manufacturing process (Figure 3) is roll-to-roll, taking advantage of low-cost thin-film manufacturing techniques. Beginning with the rolling and texturing of the metal substrate, on through the application of buffers, to silicon deposition via HW-CVD, the resultant material stack emerges with its back-reflector and back-contacting surfaces monolithically-integrated with the crystalline silicon. From this point, it can be finished into working cells and modules with PV industry-standard fabrication techniques.

Figure 3 | Ampulse Manufacturing Process - eliminates many costly Si processing steps

Unlike many other thin-film technologies where multi-junction cell architecture must be used to achieve incremental improvements in efficiency, Ampulse utilizes a simple and elegant single-junction cell architecture (Figure 4), made highly-efficient by the N-Epitaxial silicon produced in the HW-CVD process. It can be tuned in thickness to achieve a range of efficiencies from 12% to 18.5%, packaged into a flexible and lightweight module form factor, and at a fraction of the cost for traditional c-Si wafer-based PV products. While other emerging thin-film technologies claim lower manufacturing cost, they remain challenged by low efficiency and higher total system cost.

Figure 4 | Ampulse c-Si Thin-Film Single Junction Photovoltaic Cell

Ampulse’s flexible lightweight form factor is easy to install, and conveniently fits into different applications (Figure 5). The key advantages of Ampulse’s flexible roll-to-roll material include:

• Fits any size module design and form factor
• Eliminates heavy and costly glass as a substrate
• Unlike CdTe and CIGS, no panel sealing required
• Easier and less expensive to transport than glass
• Easier installation on rooftop enabling lower total system cost
• More easily fits irregular roof structures
• Integral part of Building Integrated PV (BIPV) applications

Figure 5 | Ampulse Flexible Form Factor Module - ease of installation