Date of Award
Doctor of Philosophy
Electrical and Computer Engineering
Organic light emitting diodes (OLEDs) have been widely used in commercial display technologies and are surpassing the competitors such as LCD or plasma displays in popularity. While OLEDs are excellent candidates for lighting as well for potential lower costs, compatibility with flexible substrates, and their characteristic warm and diffused light, challenges remain to be resolved before employing them in high brightness application. In this dissertation, several techniques are employed to address the major issues in the OLED technology for solid state lighting (SSL) applications and analytical on-chip sensing. To improve the light extraction from OLEDs, novel plastic substrates with nano-patterns were utilized along with a polymer anode. PEDOT:PSS (Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)) anode was spin-coated and rest of the materials were thermally evaporated to achieve a corrugated OLED conformally coated on the patterned substrates. With the corrugated OLEDs fabricated on patterned substrates, enhanced light extraction (50%-100%) was achieved over flat OLEDs. The challenges of achieving conformal coating of such substrates and their effects on the device reliability were evaluated, a potential solution was discussed to address this issue as well. Furthermore, the device architecture of white OLEDs was also modified to achieve desired color coordinates and its stability with increasing voltage. A near ultra-violet microcavity (ÃÂÃÂµc) OLED was utilized as the excitation source to achieve higher dynamic range in oxygen sensing experiment with organic photodetector. A CBP(4,4′-Bis(N-carbazolyl)-1,1′-biphenyl)-based combinatorial array of ÃÂÃÂµc OLEDs was fabricated by varying the thickness of the organic layers to obtain nine sharp, discrete emission peaks from 370 to 430 nm, which were employed in an all-organic on-chip spectrophotometer and absorption measurement of a common dye was demonstrated with set up.
Manna, Eeshita, "Enhanced Light Out-Coupling of Organic Light Emitting Devices (OLEDs) using Novel Plastic Substrates and Improved Performance of OLED-based Photoluminescence Sensing Platform" (2017). Graduate Theses and Dissertations. 15360.