Advances in mobility enhancement of ITZO thin-film transistors:a review

Indium-tin-zinc oxide(ITZO)thin-film transistor(TFT)technology holds promise for achieving high mobility and offers significant opportunities for commercialization.This paper provides a review of progress made in improving the mobility of ITZO TFTs.This paper begins by describing the development and current status of metal-oxide TFTs,and then goes on to explain the advantages of selecting ITZO as the TFT channel layer.The evaluation criteria for TFTs are subsequently introduced,and the reasons and significance of enhancing mobility are clarified.This paper then explores the development of high-mobility ITZO TFTs from five perspectives:active layer optimization,gate dielectric optimization,electrode optimization,interface optimization,and device structure optimization.Finally,a summary and outlook of the research field are presented.

Preface to Special Issue on Advanced Optoelectronic and Electronic Devices toward Future Displays--Celebration of the 10th anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies at HKUST

This year marks the tenth anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies(SKLADOT)at the Hong Kong University of Science and Technology(HKUST).The predecessor of SKLADOT was the Center for Display Research(CDR)which was started in 1995.Thus display research has a long history at HKUST.

Crystallization of amorphous silicon beyond the crystallized polycrystalline silicon region induced by metal nickel

Crystallization of amorphous silicon（a-Si） which starts from the middle of the a-Si region separating two adjacent metal-induced crystallization（MIC） polycrystalline silicon（poly-Si） regions is observed. The crystallization is found to be related to the distance between the neighboring nickel-introducing MIC windows. Trace nickel that diffuses from the MIC window into the a-Si matrix during the MIC heat-treatment is experimentally discovered, which is responsible for the crystallization of the a-Si beyond the MIC front. A minimum diffusion coefficient of 1.84×10^-9cm^2/s at 550℃ is estimated for the trace nickel diffusion in a-Si.

Kerr effect and Kerr constant enhancement in vertically aligned deformed helix ferroelectric liquid crystals

In this article,we review recently achieved Kerr effect progress in novel liquid crystal（LC） material：vertically aligned deformed helix ferroelectric liquid crystal（VADHFLC）.With an increasing applied electric field,the induced inplane birefringence of LCs shows quadratic nonlinearity.The theoretical calculations and experimental details are illustrated.With an enhanced Kerr constant to 130 nm/V2,this VADHFLC cell can achieve a 2π modulation by a small efficient electric field with a fast response around 100 μs and thus can be employed in both display and photonics devices.

胶体量子点垂直腔面发射激光器的设计与仿真

提出并设计了一种基于无机硒化镉(CdSe)量子点(QD)材料作为增益介质的垂直腔面发射激光器(VCSEL)。该方案结合量子点发光二极管(QLEDs)与分布式反馈布拉格反射镜(DBR)形成电注入量子点垂直腔面发射激光器,并在其垂直衬底方向上结合了电流注入结构及光学微腔结构。通过数值模拟的方法,进行了DBR反射镜参数设计、器件腔长调整等,得到了优化的器件结构。时域有限差分法模拟结果表明,设计的两种腔长器件均可实现单纵模激射,微腔品质因子超过250000。本研究工作提出了一种实现量子点激光二极管的新方案,并通过理论模拟进行验证,展示了此方案的可行性;同时,本工作也为下一步的实验研究提供了理论分析模型及参数指导。

Ferroelectric liquid crystals for fast switchable circular Dammann grating [Invited]

Diffractive optical elements attract a considerable amount of attention, mainly due to their potential applications in imaging coding, optical sensing, etc. Application of ferroelectric liquid crystals(FLCs) with photoalignment technology in diffractive optical elements results in a high efficiency and a fast response time. In this study we demonstrate a circular Dammann grating(CDG) with a diffraction efficiency of 84.5%. The achieved response time of 64 μs is approximately two orders of magnitude faster than the existing response time of nematic liquid crystal devices. By applying a low electric field(V = 6 V) to the FLC CDG, it is switched between the eight-order diffractive state and the transmissive diffraction-free state.

A fully self-powered, natural-light-enabled fiber-optic vibration sensing solution

Fiber-optic sensors have been developed to monitor the structural vibration with advantages of high sensitivity,immunity to electromagnetic interference(EMI),flexibility,and capability to achieve multiplexed or distributed sensing.However,the current fiber-optic sensors require precisely polarized coherent lasers as the lighting sources,which are expensive in cost and suffer from the power supply issues while operating at outdoor environments.This work aims at solving these issues,through developing a fully self-powered,natural-light-enabled approach.To achieve that,a spring oscillator-based triboelectric nanogenerator(TENG),a polymer network liquid crystal(PNLC),and an optical fiber were integrated.The external vibration drove the PNLC to switch its transparency,allowing the varia-tion of the incident natural light in the optical fiber.Compared with the majority of conventional TENG-based active vibration sensors,the developed paradigm does not suffer from the EMI,without requirements of the signal preamplifica-tion which consumes additional energy.The vibration displacement monitoring was performed to validate the sensing effectiveness of the developed paradigm.

Ionic liquid multistate resistive switching characteristics in two terminal soft and flexible discrete channels for neuromorphic computing

By exploiting ion transport phenomena in a soft and flexible discrete channel,liquid material conductance can be controlled by using an electrical input signal,which results in analog neuromorphic behavior.This paper proposes an ionic liquid(IL)multistate resistive switching device capable of mimicking synapse analog behavior by using IL BMIM FeCL_(4) and H_(2)O into the two ends of a discrete polydimethylsiloxane(PDMs)channel.The spike rate-dependent plasticity(SRDP)and spike-timing-dependent plasticity(STDP)behavior are highly stable by modulating the input signal.Furthermore,the discrete channel device presents highly durable performance under mechanical bending and stretching.Using the obtained parameters from the proposed ionic liquid-based synaptic device,convolutional neural network simulation runs to an image recognition task,reaching an accuracy of 84%.The bending test of a device opens a new gateway for the future of soft and flexible brain-inspired neuromorphic computing systems for various shaped artificial intelligence applications.