Malika Jeffries-EL, PhD
Department of Chemistry and Division of Materials Science
The past two decades has seen a dramatic increase in the number of consumer electronics in use. Previously, most households had a landline phone, one or two televisions and the occasional desktop computer. These days most people own numerous electronic devices, resulting in an increased demand on the semiconducting materials that drive this technology, in addition to the energy needed to power them. Accordingly, there has been a large amount of interest in the development of organic semiconductors, as many of the inorganic materials used in these devices are in limited supply. Organic semiconductors are either polymers or small molecules that feature and extended pi-conjugation. These materials possess many exceptional electronic, optical and thermal properties and thus are well suited for applications, such as transistors, solar cells and light emitting diodes. Unfortunately, there are several issues that have to be addressed before real-life products can be developed. Our group focuses on the design and synthesis of new organic semiconductors based on low cost and/or easily prepared starting materials. Since the properties of organic semiconductors can be readily modified through chemical synthesis, we have turned our attention towards the design and synthesis of novel aromatic building blocks. Our system of choice, benzobisazoles has many exceptional electronic, optical and thermal properties making them suitable for diverse range of organic semiconducting applications. Our group developed several new materials based on benzobisoxazoles including wide band gap materials for use in organic light-emitting diodes and narrow band gap materials for use in photovoltaic cells. We have also developed a versatile synthesis of benzodifuran, the oxygen analog of the popular electron rich building block benzodithiophene and have developing narrow band gap conjugated polymers based on it. Concurrently, we are also making molecular species based on this building block. Our work on the synthesis and properties and utility of these materials will be presented.