Research Fellows Directory
Dr Stephen Morris
University of Oxford
My research can be broadly characterised as the development of novel organic optoelectronic devices. Specifically, these are optoelectronic devices, such as lasers, displays, and photovoltaics, that are based upon soft-matter such as liquid crystals and polymers. I am particularly interested in materials that self-assemble to form macroscopic structures that remove some of the complexities that are usually associated with the fabrication of devices based upon their inorganic counterparts. For example, conventional diode lasers require a resonant cavity to be 'engineered' into the inorganic semiconductor material. However, there are certain liquid crystalline materials that naturally self-assemble to form periodic structures that mimic the cavity properties of these diode lasers, but without requiring any fabrication procedure.
In terms of laser devices, my research is focussed on developing new organic lasers with unique emission properties. For example, the spatial coherence of laser light is an important property as it specifies that the emitted light waves are in-sync with one another. Despite finding widespread use in a range of applications including consumer electronics and manufacturing, there are cases where full spatial coherence is actually undesirable as it can lead to a phenomenon known as speckle, which appears as a random intensity pattern due to the interference of the light waves. The occurrence of this speckle pattern, which negatively affects the image that is displayed, is an unwanted effect in the development of laser video displays, holography and imaging of biological systems. The aim of my research is to use these organic materials to develop laser sources that allow the spatial coherence to be controlled directly (something that is not readily achievable using conventional laser devices) thereby circumventing the issues of image degradation but retaining the other properties that typically define a laser.