Selective Solar Absorber Development for Water Heating Applications*

The goal of this research is to create and optimize a thin film material that receives solar radiation with minimal heat loss to the atmosphere to generate steam for performing work on other systems. Each thin film made in the developmental process is a combination of codeposited silicon dioxide and molybdenum that has the intent of having a high solar absorbance and low thermal emittance. The process of making these thin selective absorbers is done by a technique known as sputtering. We will present characterization data and corresponding trends with increased molybdenum that have been obtained through scanning electron microscope imaging, energy dispersive x-ray spectroscopy, ultraviolet-visible light spectrophotometry, and thermal emissivity readings. The water heating experiment requires minimal optical concentration and the use of cost-effective materials. Progress towards generating steam with our apparatus will also be presented.