Functional enhancement in Alq3 via metal doping and nanoscale synthesis: a review

Tris (8-hydroxyquinolinato) aluminum (Alq3) is an organic electron transport and luminescent material. Even after more than 20 years of intense research and development, Alq3 continues to be one of the widely used organic light emitting diode (OLED) material. Metal doping/incorporation and nanoscale synthesis are the two popular strategies used to enhance the functional properties of Alq3. This review provides an understanding about the structure and properties of Alq3. It also tries to address the long-time unresolved issue regarding the origin of blue-shifted luminescence from gamma and delta faces of Alq3. Metal doping/incorporation and nanoscale synthesis are the two widely adopted approaches to enhance the functional properties of Alq3. This review assesses the research done on these two strategies and attempts to understand the science behind adopting these strategies and the resulting performance enhancement. This review also provides an account of the research work undertaken on the relatively new direction that is nanoscale synthesis of metal-doped/incorporated Alq3 nanostructures which integrates the promises of nanoscale synthesis with the benefits of metal doping/incorporation.