Low-temperature atomic layer deposition (ALD) was employed to deposit Al 2 O 3 as a gate dielectric in amorphous In-Ga-Zn-O thin-film transistors fabricated at temperatures below 120 C. The devices exhibited a negligible threshold voltage shift (DV T) during negative bias stress, but a more pronounced DV T under positive bias stress with a characteristic turnaround behavior from a positive DV T to a negative DV T. This abnormal positive bias instability is explained using a two-process model, including both electron trapping and hydrogen release and migration. Electron trapping induces the initial positive DV T , which can be fitted using the stretched exponential function. The breakage of residual AlO-H bonds in low-temperature ALD Al 2 O 3 is triggered by the energetic channel electrons. The hydrogen atoms then diffuse toward the In-Ga-Zn-O channel and induce the negative DV T through electron doping with power-law time dependence. A rapid partial recovery of the negative DV T after stress is also observed during relaxation. V

In this paper, the transistors with excellent VTH uniformity could be fabricated by tuning oxygen content inside device. the VTH deviation of TFTs in panel is only 0.57V. Moreover, the devices we characterized show high reliability even long-term stress. Finally, we demonstrated the 31-inch 4K2K top emission OLED employing the a-IGZO TFTs.

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The common mobile communication network simulation method is to use the terminal to measure the downlink data of the base station and carry out the coverage simulation analysis of the mobile communication network. The test workload is large, the labor cost is high, and the accuracy deviation is large.The distributed base station is used to test the uplink data of the terminal, and the wireless link algorithm is used to carry out the coverage simulation analysis of the mobile communication network, so as to collect big data and high precision. Combined with the high-speed distribution processing capacity of the new generation of mobile communication network, the network test, simulation and analysis can be completed.Through verification and comparison, this method has many data sampling points, good real-time performance and high accuracy, and provides technical support for future automatic network planning and intelligent network optimization.

This paper presents a new digital protection system to solve the protection challenges in future smart grids, i.e., fast protection and fault isolation in a loop-structured system with limited magnitude of fault current. The new system combines two protection algorithms, i.e., a differential protection as the primary algorithm and an overcurrent protection as the backup one. The new system uses real-time Ethernet and digital data acquisition techniques to overcome the restriction on data transmission over large grids. The current measurements at different locations are time-synchronized by GPS clocks, and then transmitted to a central computer via the Ethernet. As opposed to digital relays which often contain PMU functionality nowadays, this approach uses time stamps on the instantaneous current values. We build a prototype of the new system on a test-bed. The results from simulations and experiments have demonstrated that the protection system achieves fast and accurate protection.