Understanding the degradation mechanism of photolithographically patterned organic photodetector by device level investigation

Near-to-eye display technology is an essential component for head-mounted AR/VR applications. For AR/VR, the resolution needs to be more than 2000/1200 PPI, and the pixel pitch must be minimized to provide a better field-of-view and ensure a natural experience. Such display can be realized by patterning organic light-emitting diode (OLED), and this can be done by photolithography, which is already well established in the semiconductor industry. Furthermore, patterning can expand the display's capability for capturing pictures and eye-tracking by integrating organic photodetector (OPD). However, device performance is affected after the patterning. In OLED, devices' efficiency and lifetime decrease significantly, causing a notable difference in power consumption and service life between devices. The impact on OPD, however, is still not fully understood. Therefore, a comprehensive study regarding the OPD degradation due to the patterning process is vital. The master thesis aims to study the impact of lithographic patterning process on OPD and to understand the degradation mechanism process behind it. The killer impurities that are introduced by the patterning process will be identified. The systematic investigation will consist of fabricating reference devices, exposing them to a series of controlled environments of chemicals, and performing analysis to map relationships and understand the phenomena.