OrganicDevice.pptVIP

Organic Device(OD) Wan Li 2010-6-13 Organic Device Preface OFET (Organic Field-Effect Transistors ) OLED (Organic Light-Emitting Diodes) OPVC (Organic Photovoltaic Cells) Process to produce organic device Potential For OD Lower cost Large area Lightweight Flexible Model problems The large π-conjugated orientation Mobility in the Organic layer By modifying molecular parameters processing condition, film thickness thermal annealing Reduce the grain size and OTS can improve Mobility Model Paper of “OLED” Problems Theory By the photovoltaic effect, electrons and holes are produced, and collected at electrodes when a device is illuminated. in the organic materials the absorption creates bound electron–hole pairs (excitons). Excitons can be dissociated by the use of combinations of materials, one with small ionization potential and good holetransport properties and the other with large electron affinity that acts as electron-transport material. Problems Efficiency in convert photon to Frenkel exciton N-type and P-type from heterojunction Carry the exciton to right place Process to produce organic device Spin-coat * * Is a potential substitute for conventional inorganic device OFET Organic Field-Effect Transistors Shtein. M et al. APL (2002)81,268 2@ with Ag contacts (annealed at 180 °C) afford the highest electron mobility of 0.51 ,which is the best device performance reported to date for solution-processed, n-type small organic molecule-based devices operating under ambient conditions. Spin-coat OLED organic light-emitting devices APL 1987 Singlet: triplet = 1 : 3 Heavy metals to make singlet to triplet possible avoid concentration quenching These devices exhibit peak external quantum and power efficiencies of 8.0% ~28 cd/A and 31 lm/W, be explained by efficient transfer of both singlet and triplet excited states in the host to Ir-ppy3, leading to a high internal efficiency. the short phosphorescent decay time of Ir-ppy ~1 ms yielding a peak luminance o