(emsl2404)Degradation mechanism of solar cells under adverse environment
EMSL Project ID
2404
Abstract
It is now widely accepted that solar energy is a major candidate for assisting with the rising global energy demands. The impact of this clean energy approach on the environment is very apparent. The portability of this energy source makes solar cells an even better candidate in remote areas and disaster environments. To make the cost compatible with other energy sources, however, solar cells must meet the following criteria: low-cost, high efficiency, good reliability and stability and they must be amenable to large-scale production. Under adverse environments such as high moisture, strong acid gases, etc, stability is a key problem. The lack of understanding of the degradation mechanisms is the major obstacle for solving the degradation problem. While experimental determination of the mechanisms faces tremendous difficulty, we believe first-principles density-functional theory may provide critical insights. The goal of this proposal is to address key degradation-related issues: a) Interaction of photovoltaic materials with molecules present in harsh environments, including molecular adsorption, dissociation, and reaction with surfaces. b) Diffusion of dissociated species in photovoltaic materials, including diffusion through bulk materials, grain boundaries and surfaces. c) Effects of the diffused species on the electronic and optical properties of photovoltaic materials, including carrier compensation, defect formation, oxidation, corrosion, carbonization, etc. The project is developed in conjunction with high-resolution transmission electron microscopy and scanning tunneling microscopy measurements, that provide atomic-resolution imaging of the structures of surfaces, grain boundaries and interfaces, and electron beam induced conductivity (EBIC) and cathodoluminescence measurements of local electronic and optical properties. The understanding of the degradation mechanism will enable us to overcome the stability problem, which will have a major impact on the environment.
Project Details
Project type
Capability Research
Start Date
2001-10-01
End Date
2003-09-25
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members