Detection of Nitrogen Organic Thin Films by Energy Dispersive X-Ray Spectroscopy and A Study on Inkjet Printing of a Thin Film Transistor

• Main Author: Castillo, Virgil Christian
• Format: text
• Published: Archīum Ateneo 2019
• Subjects: n/a
• Online Access: https://archium.ateneo.edu/theses-dissertations/396
• Institution: Ateneo De Manila University

The thesis is divided into two sections. First, is the investigation of the analysis of nitrogen concentration in different organic thin films using scanning electron microscopy with an energy dispersive X-ray spectrometer (SEM-EDS). Quantitative analysis of light elements and thin films is not routinely done using SEM-EDS due to its limitations. SEM-EDS operating conditions were optimized using design of experiments. Organic films that contained nitrogen in the form of nitrate or as part of its molecular structure were analyzed. The limit for nitrogen concentration using nitrates was 2% by mass. Below this concentration, nitrogen content had no quantifiable response to either calculated nitrogen concentration by standardless correction methods or intensity of N Kα X-ray line. However, by adding nitrate ions to a film that already contains nitrogen in its structure the concentration was raised to 13.75%. In the range of 9.63 to 13.75%, a nonlinear response was observed using calculated nitrogen concentration while the response was linear for N Kα intensity. The second part of this thesis is about solution processed thin-film transistors (TFT). Solution processing techniques is gaining widespread interest because it is more facile and cost-effective compared with conventional photolithographic techniques. Here, a study was done on the process of fabricating indium (III) oxide (In2O3)-based thin film transistors by inkjet printing. Several approaches were tested, and in general, the effect of layer thickness, ITO resistance, dielectric stability and thin film cracking on device failure was investigated to arrive at a functional transistor. Further improvements in the processing techniques need to be made to address the hysteresis in the characteristic I-V curves of the functional device.