Solar cells that conform to the shape of a three-dimensional object are desirable as a renewable energy source for self-sustaining devices (e.g., smart windows in buildings, and sensors for monitoring structural integrity in automobiles and airplanes). The conventional route for manufacturing conformal solar cells is to fabricate their functional layers onto a flexible intermediary polymer sheet, and attach the sheet onto the desired three-dimensional object. During attachment, the sheet is deformed so that it conforms to the object's three-dimensional shape. This deformation of the sheet frequently causes cracking of the cell's functional layers and a loss in the cell's functionality. This award supports scientific investigations on a new additive manufacturing process for fabricating conformal solar cells onto a three-dimensional object, without using any intermediary polymer sheet. Results from this research will enable wider use of solar cells as a renewable energy source for self-sustaining devices in energy, communications, aerospace, and automotive industries.This project aims to develop the new additive manufacturing process for conformal solar cells by integrating inkjet deposition and xenon-light-assisted nanoparticle sintering. The research objective is to understand the interaction between physio-chemical mechanisms (i.e., optically induced nanoparticle heating, temperature rise induced mass transport between nanoparticles, and mass transport induced chemical reactions) that underlie the relationship between nanoparticle characteristics (size and stoichiometry) and sintered material properties (density and chemical composition). A physics-based model will be developed by coupling optical heating of nanoparticles (via electromagnetic Finite Element Analysis), nanoscale mass transfer and reaction kinetics (using analytical models), and mesoscale evolution of temperature and stress (via mesoscale Finite Element Analysis of sintering). Certain model parameters (e.g., nanoparticle size distribution and melting points) will be calibrated by measuring nanoparticle characteristics using calorimetry, spectrophotometry, and spectroscopy. To validate the model, nanoparticles with varying characteristics will be sintered using the new process, and sintered material properties (measured using electron microscopy, X-ray diffraction, and infrared imaging) will be compared to model predictions. This validated model will be used to predict the effects of nanoparticle characteristics on sintered material properties, and on key indicators of physio-chemical mechanisms during the process (e.g., rate of temperature rise of deposited nanoparticles, shrinkage and stresses in deposited nanoparticles, and ratio of unreacted material to material with changed phase in deposited nanoparticles).
|Effective start/end date||9/1/17 → 7/31/19|
- National Science Foundation (National Science Foundation (NSF))