Who In Their Right Mind Would Patent This? • Only 0.01% efficiency but not optimised in any way: Large injection barriers: ∆φ > 1eV Poor transmission through metal electrodes Low photoluminescence quantum efficiency: Φ ≈ 24% • Target 1% efficiency (N.B. no GaN/GaInN, AlGaAs MQW diodes at that time) • Red, Green, Blue possible via chemistry (N.B. No good blue diodes at that time - main focus was on SiC) • Desirability of solution fabrication process was recognised • Potential for fast response as needed for video • Decided to patent: Technology transfer office (Lynxvale) had no money to cover patent costs!
Conjugated Polymer LED Impact •First paper published in Nature 1990 (Has > 6800 ISI citations, the most cited paper in Plastic Electronics) “Light-Emitting Diodes based on Conjugated Polymers” J.H. Burroughes, D.D.C. Bradley, A.R. Brown, R.N. Marks, K.D. Mackay, R.H. Friend, P.L. Burn, and A.B. Holmes: Nature 347 (1990), 539 - 541 • Major Scientific Impact: Triggered an explosive growth in the science and application of Plastic Electronic materials and devices c.f. Nature Physics Portal - Looking Back (Most prominent Physics papers published in Nature since 1869): www.nature.com/physics/looking-back/burroughes/index.html