UCF researchers have combined technologies from two industries, photovoltaics (PV) and displays, to create a unique design using a double layer anti-reflective coating (DLARC) with atmospheric pressure chemical vapor deposition (APCVD) oxide films, specifically with the use of aluminum oxide (AlOx). This advanced method significantly improves resistance to moisture intrusion and passivation degradation. Additionally, AlOx as a top layer in a film stack provides superior optical performance due to its high transparency and a compatible refractive index. AlOx can also possibly act as a sodium diffusion barrier in c-Si solar cells, reducing potential induced degradation.
This DLARC design is comprised of a first ARC layer formed closer to the optically active semiconductor substrate and containing at least one dielectric material such as silicon dioxide (SiO2) or titanium dioxide (TiO2) and a second ARC layer located over the first anti-reflective coating layer containing AlOx. This method also includes collecting an electrical output from the PV cell.
Previous multi-layer APCVD oxide films used only SiO2 and TiO2, which are both water permeable, causing subsequent degradation during damp heat testing. Compared to the typical use of plasma-enhanced chemical vapor deposition (PECVD) SiNx as a single layer anti-reflection coating, this invention offers reduced reflectance when integrated over the relevant solar spectrum, resulting in an increase in the short circuit current density of the cell as well as increased efficiency. Moreover, the DLARC APCVD oxide film stack is less expensive to produce than PECVD SiNx, primarily because both films can be deposited with one in-line multi-chamber APCVD tool that features no vacuum components and significantly reduced footprint and complexity.
- Improved resistance to moisture intrusion and passivation degradation
- Less expensive to produce
- Superior optical performance
- Increased efficiency
- Solar cell manufacturing