High-Throughput Optical Mapping for Accelerated Stress Testing of PV Module Materials

Recipient NREL (PI: Miller, David)

Subs NREL

Status Awarded

Abstract Testing of material coupons (e.g. 2”x2” samples, see Figure ) is an established method to evaluate a wide variety of PV packaging materials for purposes including screening and degradation rate modeling To parallelize testing of a variety of materials, many coupons or sets of coupons can be simultaneously aged in standard or custom Weather-ometers at NREL. However, for optical performance characterization (hemispherical and diffuse transmittance), the coupons are presently measured one at a time using a commercial spectrophotometer. This slow and labor-intensive measurement process substantially limits the scope and size of coupon studies and further, usually only the center of the coupon is measured. However, prior studies show that degradation and consequent material damage are often spatially distributed as a function of water and oxygen ingress with the size of the affected region being material (formulation) dependent [2], indicating a clear need for study in the development of future materials. In this project, we will develop a spectroscopy capability that will enable automated measurements of arrays of coupons as well as spatial mapping within a coupon to accelerate research. In addition, the switch from a scanning spectrophotometer with a point detector (which measures one wavelength at a time) to CCD array-based spectrometers (which measure the full spectrum simultaneously) will reduce the spot measurement time from ~6 minutes per spot to ~ 5 seconds. Further, all the measured spectra will also be automatically harvested and made available via the DuraMAT datahub.