Low temperature fabrication of printed p-type CuI TFTs was reported for the first time.

Compared to conventional amorphous silicon (a-Si) TFTs, amorphous metal oxide TFTs have superior device performance such as higher mobility, better sub-threshold swing, and lower off-state current. Amorphous metal oxide TFTs have an additional advantage on the device uniformity due to the lack of grain boundary issues in the poly-Si TFTs. Compared with sputtered oxide TFTs, metal oxide TFTs with solution processes have better flexibility and controllability to adjust the composition of chemical solution. Among various solution-based approaches, direct printing is a promising low-cost technique in fabricating TFTs. The printing technique offers several advantages in manufacturing electronics such as a direct writing of materials, reduction of chemical waste, and reproducibility with high-resolution scale, which are not affordable from other solution-based approaches. While many printed OTFTs have been reported, relatively fewer studies, associated with printed metal oxide TFTs, have been pursued. Interests to printed metal oxide TFTs have grown continuously since the first report of a general route toward printed oxide TFTs. A variety of metal oxide materials have been reported as the channel layer of printed metal oxide TFTs. In this mini review paper, the development of printed metal oxide TFTs was discussed including the ink formulations, the types and characteristics of the applied printers, and fabricated thin film transistor characteristics. Lastly the review is concluded with a concise summary and future outlook from an industry perspective. Thin film transistors (TFTs), first reported by Lilienfeld and Heil almost nine decades ago, have continuously being developed and improved for low cost electronic switches.1,2 Advanced fabrication techniques and materials expand its application to low cost, large size, high resolution, and high-speed flat panel displays.3 The greatest advancement was accompanied with the advent of a-Si:H as a semiconductor channel layer.4 Although a-Si:H semiconductor exhibited lower electronic properties (carrier mobility ≤ 1 cm 2 /Vs) than TFTs based on polycrystalline channel layers (e.g. CdS), the electronic transport properties of a-Si:H were sufficient as switching elements in Liquid Crystal Displays, along with other benefits such as lower cost, high uniformity and excellent reproducibility in large area fabrication. However, lower performances of a-Si:H TFTs limit its application in AMOLED display. Metal oxide semiconductors have been intensively researched over the past decade due to their superior electrical properties including high carrier mobility (∼1-100 cm 2 /Vs), high optical transparency, good thermal/environmental durability, and potentially low-manufacturing cost.5,6 Significant progress of metal oxide TFTs has demonstrated the advantages over a-Si:H TFTs as next candidate for high-performance display applications. 7,8 In terms of manufacturing metal oxide semiconductors as the active channel layers in TFTs, gas-phase deposition technique that requires high vacuum f...

Unlike previous high-contrast devices that all involve inserting extra layer͑s͒ with optical purposes ͑e.g., absorption and interference͒ into the active region of devices, in this-letter we report a high-contrast top-emitting organic light-emitting device ͑OLED͒ that utilizes only optical characteristics of electrodes and anti-reflection coatings deposited outside the active region, thus reducing the complexity of devices. Furthermore, the device has an inherent microcavity which is beneficial to electroluminescence efficiency. The devices are readily compatible with the processing of active-matrix backplanes, and active-matrix OLED displays incorporating such high-contrast top-emitting devices were demonstrated to have improved readability under a strong lighting environment.

In this study, we fabricate amorphous indium oxide thin film transistors (TFTs) on a display glass substrate at various annealing temperatures from 200 °C to 300 °C.