本所教师指导硕、博士生荣获以下各奖项，特此恭贺！

本所吴育任教授、姚力琪小姐、简璟小姐代表本所参加电资学院队，荣获本校2023学年度（74届）全校运动会教职员工组1200公尺混合接力赛第三名，特此恭贺！

本所12月份演讲公告 ：

～ 光电所所属实验场所小型紧急应变演练 ～

（时间：2023年11月1日，下午2:30~3:00）

整理：简璟

演练地点：电机二馆334A、334B室

演练内容：

本次演练主要目的为使人员在实验室意外灾害事故发生时各司其责，采取正确而有效方式控制灾害，并落实实验室人员具备紧急逃生之观念与方式，以提高紧急状况时的应变能力。

下午2时30分于电机二馆334A、334B实验室，假设学生进行实验时，发生电线走火火灾意外，学生紧急通报所办公室人员。本所人员接获通报后，即刻联系馆舍电机系办人员协助广播疏散全馆；并紧急分组编派人员：于出口引导疏散人员尽速远离馆舍、协助火势控制、进行灭火、设置人员禁止进入标示、设置救护站协助受伤同学、于集合区清点确认疏散人员名单。所办人员同时持续紧急联系电机二馆334A实验室负责教师（陈奕君教授）、所长（吴育任教授）及本所环安卫委员（林建中教授）前往电机二馆南侧出口广场前集合；由所长、环安卫委员掌握现场状况并进行指挥调度，确核实验室全部人员疏散完毕，顺利完成此次疏散演练。

此次疏散演练加强了大家在意外发生时，能实时进行紧急通报及疏散的观念。感谢教师、同仁及同学们的全力配合。

Low-Cost 3D-Printed Large-Area 1-DOF Scanners

Professor Jui-che Tsai

Graduate Institute of Photonics and Optoelectronics, National Taiwan University

台湾大学光电所 蔡睿哲教授

We have developed 3D-printed 1-DOF (one torsional axis; 1 degree of freedom) optical scanners with large mirror areas (up to 20 × 20 mm²). Each device consists of an aluminum-coated square silicon substrate serving as the mirror, two miniature permanent magnets, an electromagnet, and a 3D-printed structure including the mirror frame, torsion springs, and base. One device can reach a static half optical deflection angle of 14.8 deg. at 12 VDC; this particular device exhibits a mechanical resonance frequency of 84 Hz. These scanners can be a potential, low-cost alternative to the expensive conventional galvanometer scanners.

Shen, C.-K.; Huang, Y.-N.; Liu, G.-Y.; Tsui, W.-A.; Cheng, Y.-W.; Yeh, P.-H.; Tsai, J.-c.*, “Low-Cost 3D-Printed Electromagnetically Driven Large-Area 1-DOF Optical Scanners,” Photonics, vol. 9, no.7, 484, Jul. 2022.

Carrier localization in III-nitride versus conventional III-V semiconductors: A study on the effects of alloy disorder using landscape theory and the Schrödinger equation

Professor Yuh-Renn Wu's Laboratory

Graduate Institute of Photonics and Optoelectronics, National Taiwan University

台湾大学光电所 吴育任教授

Semiconductor devices often necessitate the practice of band-gap engineering, a process that involves the utilization of alloys and the fine-tuning of their composition to achieve the desired electrical or optical characteristics. While deviations in composition are typically considered minor perturbations in conventional III-V semiconductors, the impact of alloy disorder is significantly more pronounced in III-nitrides. This study aims to compare the influence of alloy disorder on carrier localization, focusing on various III-V semiconductors, particularly with regard to holes, where localization effects are more pronounced due to their greater effective mass.

To conduct this investigation, we employ three-dimensional computational methods for III-V alloys featuring natural (random) compositional fluctuations. Given the intricacy of the problem, our computations are based on a simplified Hamiltonian within the envelope wave-function approximation, focusing on a single heavy-hole valence band. We explore the impact of compositional fluctuations on carrier localization using two distinct approaches.

The first approach leverages the localization landscape theory, allowing us to solve the localization landscape equations and derive the effective potentials that act upon carriers. These potentials serve as confining forces, predicting the spatial regions where carriers are most likely to be localized. This enables a comparative analysis of the effects of alloy fluctuations between conventional III-V and III-nitride semiconductors. Notably, we observe that the effective potential in III-nitride semiconductors exhibits considerably larger fluctuations compared to other III-V semiconductors, potentially indicating a higher degree of carrier localization in nitrides, particularly for holes.

To validate this observation, we employ the second method, solving Schrödinger's equation to determine the electron and hole wave functions. Our findings reveal that in In_xGa_1−xN, electron wave functions tend to be delocalized, even in the ground state, while low-energy hole states exhibit localization. This contrasts with the behavior of holes in the common alloy In_xGa_1−xAs, where they are consistently found to be delocalized. Thus, our study underscores the significance of accounting for alloy disorder in nitride semiconductors.

This work is published in Phys. Rev. Applied, 20, 044069 (2023).

DOI: 10.1103/PhysRevApplied.20.044069

论文题目：石墨烯于半导体后端制程的应用

姓名：黄健治   指导教授：吴志毅教授

摘要

我们使用低温成长技术在金属导线上形成石墨烯层，以利用其独特的特性来降低金属互连的电阻。实验结果证明，石墨烯的覆盖不仅可以降低金属互连的电阻，还可以提高其能承受的最大电流密度。此外，石墨烯的覆盖还增强了金属互连的表面活化能，从而延长了其电致迁移的寿命。 同时考虑了使用多层石墨烯来替代传统的金属互连。多层石墨烯独特的特性使其免受到导线微缩导致电阻率增加的影响，因此被视为半导体后端互连的理想材料。然而，制造高质量的多层石墨烯仍然是一个挑战。为此，我们提出了一种新方法，能够迅速生长高质量的石墨烯，并能够精确地控制其层数。结合插层技术，我们成功地降低了多层石墨烯的片电阻，使其电阻率接近于铜。这为多层石墨烯替代传统的金属互连带来了重大突破。此外，要将其实际应用于半导体后端制程，金属与石墨烯互连的接触电阻至关重要，因此我们深入研究了如何降低金属与石墨烯互连的接触电阻，并提出了几种有效的方法。在研究的最后部分，我们还结合了其它过渡金属二硫化物来制造范德瓦晶体管，并成功证实了透过范德瓦接触可以解决钉扎效应的问题。 图一、石墨烯覆盖金属互连耐久度提升4.5x 图二、石墨烯的片电阻使其电阻率接近于铜

— 资料提供：影像显示科技知识平台 (DTKP, Display Technology Knowledge Platform) —

— 整理：林晃岩教授、黄茂恺 —

非厄米规范激光数组

非厄米表皮效应（non-Hermitian skin effect, nHSE）是一种在具有虚数规范场（imaginary gauge field）的非厄米系统（non-Hermitian system）中发现的拓扑现象，为一种在开放边界上积累巨观数量边缘态的系统。它之所以引人关注，是因为其产生指向的各向异性传输和相位锁定在理论上都能够实现，而且也对于扰动和动力学不稳定性具有强韧性。因为这些有趣的特性的启发，来自美国和印度的Zihe Gao及其合作者，现在展示了一个二维（2D）激光数组，它扮演了一个非厄米规范的激光数组（non-Hermitian gauged laser array, nHGLA），在芯片上具有可重新配置（reconfigurable）的非对称耦合（Z. Gao et al., Phys. Rev. Lett. 130, 263801; 2023）。

这个非厄米规范激光数组（nHGLA）是由一组200奈米厚的InGaAsP多重量子井的微环激光组成（如图一所示）。微环的内半径为3微米，宽度为600奈米。为了引入最邻近的微环腔之间的非对称耦合，它们被螺旋形的耦合臂连接着。

当nHGLA受到脉冲激光（波长1,064奈米，脉冲持续时间8奈秒）激发时，每个微环腔产生两个退化的激光模态，分别在顺时针和逆时针方向，被视为拟自旋（pseudospin）。为了萃取激光模态的光，而且实现超快且可控的非良好定义的规范场，该研究中在微环的内侧壁上刻制了周期性的散射体，并透过使用空间光调制器，对每个拟自旋进行了非对称的光学激发，从而破坏了它们之间的耦合对称性。

nHGLA的相位锁定是透过单向耦合实现的。当虚数规范场在x和y方向均具有单向耦合且均匀时，nHSE会产生了角模态。然而，当虚数规范场在二维晶格中改变方向时，nHSE会产生局限于领域边界的界面模态。

光学模态的局部化程度随着耦合臂中的放大而增加。此外，虚数规范耦合所带来的放大也对总输出功率的增加有所贡献，超越了未耦合环的简单的加总。

该平台有望可以实现一个可重新配置与高亮度的光源架构。