The optoelectronic materials developed in COPE are often designed with distinct optical properties in mind. For example, in the case of solar cells, materials are designed that have the ability to strongly absorb sunlight over a wide wavelength range. In contrast, luminescence-based sensors rely on changes in the fluorescence signal to detect an analyte. COPE has access to wide range of spectroscopic techniques that enables it explore the fundamental photophysical properties of organic semiconductor materials.