| The biopolymer deoxyribonucleic acid (DNA) has been extracted from salmon (saDNA) and used successfully as an electron blocking layer (EBL) in multiple structures of Organic Light Emitting Diodes (OLED). Water soluble saDNA was complexed with a cationic surfactant hexadecytrimethylammonium chloride (CTMA) which makes the resulting DNA-CTMA molecule water insoluble, and soluble in common organic media such as alcohols. Solutions of DNA-CTMA and butanol make uniform thin films from 20nm to 5 microns in thickness by varying spin coating parameters and molecular weight. The optical properties of DNA-CTMA thin films include high transparency and low optical loss for applications at wavelengths above 400nm. The DNA-CTMA films have an electrical resistivity on the order of 107 O*cm.; All of these properties combined made DNA-CTMA a candidate as an EBL in OLEDs, and this resulting device was termed a Bio-organic Light Emitting Diode (BioLED). Enhanced electroluminescent efficiency has been demonstrated in both green and blue emitting BioLEDs. The resulting green and blue BioLEDs showed a maximum luminous efficiency of 8.2 and 0.8 cd/A, respectively. The DNA based BioLEDs were as much as 10x more efficient and 30x brighter than their OLED counterparts. The enhancement in performance is due to the electron blocking action with the 0.9 eV (lowest unoccupied molecular orbital) value, allows hole injection to proceed with a 5.6eV (highest occupied molecular orbital) value.; DNA-CTMA has also been successfully deposited in thin film form via molecular beam deposition (MBD). The growth was achieved at 160°C at vacuum levels of 10-5 Torr at a deposition rate of 0.8A/s. MBD grown DNA-CTMA thin films were highly uniform, optically transparent, and adhere to silicon, quartz and glass substrates more strongly than spin coated films. The material deposited was verified as DNA-CTMA through optical absorption, energy dispersive X-ray analysis, and using a DNA indicating fluorescent dye.; This thesis is the result of a research collaboration between the University of Cincinnati and the US Air Force Research Laboratory. At AFRL, research was performed in the Materials Directorate supervised by Dr. James Grote. At UC, research was performed in the Nanoelectronics Laboratory and supervised by Prof. Andrew Steckl. |
