Researchers look to organic materials as they develop novel sensors
1 min read
Optical components can be found in applications ranging from automation technology and bioanalytics to medical imaging. The components are typically made from inorganic materials, such as silicon, but researchers from Fraunhofer's Institution for Organics, Materials and Electronic Devices researchers are also developing organic photodiodes (OPD). "These kinds of device offer a range of advantages compared with inorganic components – they're lightweight, cheap to produce and can be used for flexible applications," said Dr Olaf Hild.
The choice of which material to use is determined primarily by the wavelength spectrum for the particular application. By choosing the right material, scientists can control and tailor the sensor's spectral sensitivity. Materials are available to cover a broad range of the spectrum, but special applications can be catered for with compact microsensors that combine organic semiconductors with silicon technology.
Applications are said to range from tiny sensor elements for cameras to large scale quality control. In lab on chip devices, OPDs can detect DNA sequences that have been tagged with fluorescent markers. Dr Hild said: "Integrating our OPDs increases the light sensitivity of today's CCD chips by providing a larger usable surface."
Unlike silicon based devices, OPDs enable flexible components. Photodiodes can be integrated into polymer films and applied to curved surfaces. This could enable custom quality control systems; for example, car doors could be examined for scratches or quality inconsistencies in the paintwork.
OPDs may also offer a cheaper alternative to traditional technologies when it comes to large areas; they can be applied to comparatively inexpensive materials using simple coating techniques.
