US National Institute of Standards and Technology (NIST) recently announced that the agency researchers use two new technologies, the first nano-precision detection of widely used solar cells, chemical composition and defects in the changes. The new technology detects common solar cells made of cadmium telluride semiconductors, which is expected to help scientists better understand the microstructure of solar cells and may propose ways to further improve the efficiency of solar photoelectric conversion.
In the study, NIST scientists used two methods of relying on atomic force microscopy (AFM) to measure the amount of light absorbed by the light-induced resonance (PTIR) in the wide wavelength range from visible to mid-infrared, resulting in nanoscale Get the composition of solar cells and their defects. Another technique, known as a scanning near-field optical microscope (dt-NSOM), captures changes in the composition and defects of solar cells by recording the amount of light transmitted at a particular location to form a detailed nanoscale image.
Experiments show that the defects of the crystal arrangement of the material are related to the impurities in the chemical composition. The new technology can detect the spatial variation of the so-called deep defect in the cadmium telluride sample. These defects cause cadmium telluride to recombine with electrons and protons (positively charged particles) in other semiconductors rather than to generate electricity, which is one of the key reasons why solar cells can not achieve theoretical results.
The research results have a wide range of applicability that will help solar cells to better understand the various photovoltaic materials. The study was published in the April 12, 2017 issue of Nanoscale.