FULL PAPER © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 6170 wileyonlinelibrary.com active-matrix organic light-emitting diode (f-AMOLED) is potentially strong candi- dates for use in these devices, as they have high optical transparency exceeding 80% [3] with outstanding performance capabili- ties, as exemplified by their rapid refresh rates, short response time, and low power consumption levels. [4,5] The backplane of oxide thin-film tran- sistors (TFTs) has been spotlighted as a switching and driving component for transparent f-AMOLED due to its high mobility, [6] low leakage current, [7] and high transparency. [8] Several research groups have reported various approaches to create flexible oxide TFTs by means of direct deposition onto plastics, [9] solution-coating methods, [10,11] and with composite-based nanomaterials. [12] These methods, how- ever, are associated with the fact that the oxide TFTs on flexible substrates exhibit insufficient performance levels and low production yields compared to those on conventional glass substrates, owing to the inherent issues of high-temperature compatibility [13] or their yellowish plastic color. [14] Our group has recently developed high-performance flexible one selector-one memristor (1S-1M) devices utilizing an inorganic-based laser liftoff (ILLO) process, [15] an advanced exfoliation process for transferring only inorganic thin- film devices fabricated on a rigid substrate onto a large-area plastic substrate. While the application of flexible high-density memory has been investigated, the ILLO process has not been exploited for display technology, where the largest flexible elec- tronic market exists. Recently, skin-like electronics (thickness <5 μm, transmit- tance >80%) that can be conformally attached onto any type of curvilinear surface have been reported for human/machine interfaces, wearable technologies, and biomedical applica- tions. [16,17] Despite the demonstrations of ultrathin electronics such as organic thin-film transistors [18] and strain sensors, [19–21] the skin-like display remains as a challenge to achieve next-gen- eration imperceptible displays or display of things. Here, we realize high-performance, skin-like, transparent oxide TFT arrays using the ILLO process. The 50 × 50 indium zinc oxide (IZO) TFT array, fabricated with a laser-reactive exfo- liation layer on a rigid glass substrate, was successfully trans- ferred onto an ultrathin flexible substrate (4 um thickness). After irradiation by an excimer laser through the backside of the Skin-Like Oxide Thin-Film Transistors for Transparent Displays Han Eol Lee, Seungjun Kim, Jongbeom Ko, Hye-In Yeom, Chun-Won Byun, Seung Hyun Lee, Daniel J. Joe, Tae-Hong Im, Sang-Hee Ko Park,* and Keon Jae Lee* Flexible transparent display is a promising candidate to visually communicate with each other in the future Internet of Things era. The flexible oxide thin- film transistors (TFTs) have attracted attention as a component for trans- parent display by its high performance and high transparency. The critical issue of flexible oxide TFTs for practical display applications, however, is the realization on transparent and flexible substrate without any damage and characteristic degradation. Here, the ultrathin, flexible, and transparent oxide TFTs for skin-like displays are demonstrated on an ultrathin flexible substrate using an inorganic-based laser liftoff process. In this way, skin-like ultrathin oxide TFTs are conformally attached onto various fabrics and human skin sur- face without any structural damage. Ultrathin flexible transparent oxide TFTs show high optical transparency of 83% and mobility of 40 cm 2 V -1 s -1 . The skin-like oxide TFTs show reliable performance under the electrical/optical stress tests and mechanical bending tests due to advanced device materials and systematic mechanical designs. Moreover, skin-like oxide logic inverter circuits composed of n-channel metal oxide semiconductor TFTs on ultrathin, transparent polyethylene terephthalate film have been realized. DOI: 10.1002/adfm.201601296 H. E. Lee, Dr. S. Kim, J. B. Ko, H.-I. Yeom, S. H. Lee, Dr. D. J. Joe, T.-H. Im, Prof. S.-H. K. Park, Prof. K. J. Lee Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro, Yuseong-gu Daejeon 34141, Republic of Korea E-mail: shkp@kaist.ac.kr; keonlee@kaist.ac.kr C.-W. Byun Information & Communications Core Technology Research Laboratory Electronics and Telecommunications Research Institute (ETRI) 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea 1. Introduction Augmented reality (AR) [1] has attracted significant attention with the development of smart devices and the Internet of Things (IoT), [2] which can realize a hyperconnected society by collecting and exchanging bilateral information. Flexible trans- parent displays have been proposed as a powerful medium of visual communication that can be attached to anything, including the windows of vehicles and buildings, mirrors, and even eyeglasses for the efficient use of space. Flexible Adv. Funct. Mater. 2016, 26, 6170–6178 www.afm-journal.de www.MaterialsViews.com