In recent years, deoxyribonucleic acid (DNA) biopolymers have attracted much research attention and been considered as a promising material when being employed in many optoelectronic devices. Since performance of many DNA biopolymer-based devices relies on carrier transport, it is crucial to study the carrier mobility of these DNA-surfactant complexes for practical implement. In this work, we present hole mobility characterization of cetyltrimethylammonium (CTMA)-modified DNA biopolymer by using space-charge-limited current (SCLC) method. Devices were fabricated using a sandwich structure with a buffer layer of MoO3 to enhance hole injection and achieve ohmic contact between the anode and the DNA layer. Current-voltage (I-V) curves of the devices were analyzed. A trap-free SCLC behavior can ultimately be achieved and a quadratic dependence in I-V curve was observed. With increasing electric field, a positive field-dependent mobility was demonstrated. The correlation between mobility and temperature was also investigated and a positive relation was found. The characterization results can be further utilized for DNA-based device design and applications.
Deoxyribonucleic acid (DNA) biopolymers have shown promise to be utilized in optoelectronic devices owing to several unique features of DNA molecules. In this study, we present the fabrication of DNA-Au nanoparticles (Au NPs) nanocomposite and incorporate it in organic light-emitting devices (OLEDs). DNA biopolymer attributes to a high lowest unoccupied molecular orbital (LUMO) level for electron blocking, whereas Au NPs are the hole traps to retard hole injection. We evaluate the performance of DNA-Au NPs nanocomposite OLEDs comprised of different concentrations of Au NPs. The results indicate that the utilization of DNA-Au NPs nanocomposite gives rise to higher luminance and higher current efficiency compared to the DNA-based device without Au NPs.