Flexible IGZO TFTs and their Suitability for Space Applications

In this paper, Low Earth Orbit radiation (LEO), temperature and magnetic field conditions are mimicked to investigate the suitability of flexible InGaZnO transistors for lightweight space wearables. More specifically, the impacts of high energetic electron irradiation with fluences up to e12e-, low operating temperatures down to 78 and magnetic fields up to 11 are investigated. This simulates 278 in LEO. The threshold voltage and mobility of transistors that were exposed to e- irradiation are found to shift by +separate-uncertainty0.09± 0.05 and -separate-uncertainty0.6± 0.52-1-1. Subsequent low temperature exposure resulted in additional shifts of +0.38 and -5.952-1-1 for the same parameters. These values are larger than the ones obtained from non-irradiated reference samples. Conversely, the performance of the devices was observed not to be significantly affected by the magnetic fields. Finally, a Cascode amplifier presenting a voltage gain of 10.3 and a cutoff frequency of 1.2 is demonstrated after the sample had been irradiated, cooled down and exposed to the magnetic fields. If these notions are considered during the systems’ design, these devices can be used to unobtrusively integrate sensor systems into space suits.