| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Solar Cell Silicon
|
| Presentation Title |
First Principles Modeling of Water-induced Polymer Encapsulant Degradation in Silicon Modules |
| Author(s) |
Arun Kumar Mannodi Kanakkithodi, Rishi E. Kumar, David Fenning, Maria K.Y. Chan |
| On-Site Speaker (Planned) |
Arun Kumar Mannodi Kanakkithodi |
| Abstract Scope |
An outstanding issue in Si photovoltaic modules is the accelerated degradation caused by the presence of moisture, which leads to interfacial instability, encapsulant decomposition and corrosion at contacts. In this work, we use density functional theory (DFT) to model the structure and degradation mechanisms of ethylene vinyl acetate (EVA), the most common polymer encapsulant used in Si PV modules. Infrared active modes computed for EVA crystalline structures match well with reported experiments. The Nudged Elastic Band (NEB) method is applied to model decomposition mechanisms of EVA, with and without the presence of moisture; computed energy barriers show a preference for acetic acid formation and are lowered by the presence of a solvent or catalyst such as a proton or hydroxyl ion. This systematic study leads to a clear picture of the hydrolysis-driven decomposition of EVA in terms of energetically favorable mechanisms, possible intermediate structures, and IR signatures of reaction products. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |