Executive Summary : | Flexible electronics refers to those electronic devices that retain their device performance under a mechanical stress such as bending, folding, twisting, stretching etc. Owing to their flexibility, these devices have immense potential for applications in different fields ranging from prosthetics to displays. The discovery of conducting polymers based on π-conjugated systems opened up the field of organic electronics and has since revolutionized the development of flexible electronic devices. However, despite their beneficial properties, a majority of the polymer based systems lose their emission under mechanical stress and are also not economically viable thus necessitating the need for the development of simple alternatives that are easy to synthesize and process. Single crystals of small organic compounds are ideal as they are known to be defect-free and thus exhibit superior device performance. However, the inability to withstand mechanical deformation restricts their utility in flexible devices. This proposal aims to address this challenge by employing flexible organic single crystals for electroluminescent devices. Motivated by our recent research on flexible organic crystals, we propose to synthesize a series of small organic compounds from readily available starting materials. These compounds will be functionalized appropriately incorporating design elements that facilitate the formation of flexible organic crystals. Further, moieties that aid in the formation of charge-transfer states will also be included which will help in imparting luminescence and ferroelectric properties. Our synthesis strategy further allows for the preparation of several compounds from the same set of starting materials. The resultant compounds will be screened for mechanical flexibility, luminescence and ferroelectric properties, and the best candidate will be used for device fabrication. A substrate-free device fabrication method is proposed for ensuring efficient and stable light emission while being highly flexible. This proposal is expected to produce flexible electroluminescent devices incorporating single crystals. Owing to the inherent flexibility and crystalline nature, these devices will exhibit good light emission under mechanically deformed states. If successful, this project will thus deliver novel electroluminescent devices in short term and has the potential to contribute towards the development of flexible displays in the long term. |