Organic Semiconductors: Applications in Solar Photovoltaic and Sensor Devices

Organic semiconductor-based solar photovoltaic cells and sensors are scalable, printable, solution processable, bendable and light-weight. Furthermore, organic semiconductors require low energy fabrication process coupled with the ease of processing, as well as compatibility with flexible substrates, hence, can be fabricated at low cost as light-weight solar cells and sensors. Organic semiconductors have been identified as a fascinating class of novel semiconductors that have the electrical and optical properties of metals and semiconductors. The continuous demand to improve the properties of organic semiconductors raises the quest for a deep understanding of fundamental issues and relevant electronic processes. Organic semiconductor thin film is sandwiched between two metal electrodes of indium tin oxide (ITO) and aluminum to form organic photovoltaic solar cell. Several types of organic semiconductors have been utilized as the photoactive layer in the solution processable organic solar cells. The performance of the fabricated solar cells can be improved by dissolving the material in the right choice of solvent, annealing of organic thin film, slowly forming the thin film and introducing an infra-red absorbance layer. Besides, organic semiconductor-based sensors can be fabricated utilizing either in a sandwich type or planar type device. Some of these techniques and the experimental results are presented.