柔性自发光器件是当前照明和显示领域的前沿课题。相比有机发光二极管，无机半导体具有更稳定的物理化学性质，但晶态无机薄膜不具有良好柔韧性，因此，低维纳米线阵列结构成为柔性器件研究新的突破方向。铯铅卤化物钙钛矿量子点具有高发光量子产率，将钙钛矿量子点作为荧光层分散在纳米线阵列中，可以利用钙钛矿材料的高荧光效率，实现可见波段柔性器件。首先制备了氧化锌 (ZnO)/氧化镁 (MgO)纳米线阵列异质结构，在柔性锌箔基片上构建了金属/绝缘体/半导体异质结光发射器件，实现了源自ZnO纳米线的本征紫外发射和电泵浦紫外随机激光。进而采用纳米线异质结作为短波长激发源、钙钛矿量子点作为荧光层，实现了柔性荧光型暖白光原型器件。

Miniaturized light sources at telecommunication wavelengths are essential components for on-chip optical communication systems. Here, we report the growth and fabrication of highly uniform p-i-n core-shell InGaAs/InP single quantum well (QW) nanowire array light emitting diodes (LEDs) with multi-wavelength and high-speed operations. Two-dimensional cathodoluminescence mapping reveals that axial and radial QWs in the nanowire structure contribute to strong emission at the wavelength of ~1.35 and ~1.55 μm, respectively, ideal for low-loss optical communications. As a result of simultaneous contributions from both axial and radial QWs, broadband electroluminescence emission with a linewidth of 286 nm is achieved with a peak power of ~17 μW. A large spectral blueshift is observed with the increase of applied bias, which is ascribed to the band-filling effect based on device simulation, and enables voltage tunable multi-wavelength operation at the telecommunication wavelength range. Multi-wavelength operation is also achieved by fabricating nanowire array LEDs with different pitch sizes on the same substrate, leading to QW formation with different emission wavelengths. Furthermore, high-speed GHz-level modulation and small pixel size LED are demonstrated, showing the promise for ultrafast operation and ultracompact integration. The voltage and pitch size controlled multi-wavelength high-speed nanowire array LED presents a compact and efficient scheme for developing high-performance nanoscale light sources for future optical communication applications.

This paper reports the fabrication of regular large-area laser-induced periodic surface structures (LIPSSs) in indium tin oxide (ITO) films via femtosecond laser direct writing focused by a cylindrical lens. The regular LIPSSs exhibited good properties as nanowires, with a resistivity almost equal to that of the initial ITO film. By changing the laser fluence, the nanowire resistances could be tuned from 15 to 73 kΩ/mm with a consistency of ±10%. Furthermore, the average transmittance of the ITO films with regular LIPSSs in the range of 1200–2000 nm was improved from 21% to 60%. The regular LIPSS is promising for transparent electrodes of nano-optoelectronic devices—particularly in the near-infrared band.

The AlGaN/GaN p–n junction has received extensive attention due to its capability of rapid photogenerated carrier separation in photodetection devices. The AlGaN/GaN heterojunction nanowires (NWs) have been especially endowed with new life for distinctive transport characteristics in the photoelectrochemical (PEC) detection field. A self-powered PEC ultraviolet photodetector (PEC UV PD) based on the p-AlGaN/n-GaN heterojunction NW is reported in this work. The n-GaN NW layer plays a crucial role as a current flow hub to regulate carrier transport, which mainly acts as a light absorber under 365 nm and carrier recombination layer under 255 nm illumination, which can effectively modulate photoresponsivity at different wavelengths. Furthermore, by designing the thicknesses of the NW layer, the photocurrent polarity reversal was successfully achieved in the constructed AlGaN/GaN NW PEC UV PD at two different light wavelengths. In addition, by combining with platinum decoration, the photoresponse performance could be further enhanced. Our work provides insight into transport mechanisms in the AlGaN/GaN NW PEC system, and offers a feasible and comprehensive strategy for further exploration of multifunctional optoelectronic devices.

针对目前低维材料转移方案中过程复杂和衬底适应性差的难题，提出了一种常温常压下基于柔性聚合物薄膜聚二甲基硅氧烷（polydimethylsiloxane, PDMS）的低维材料定点转移方法。PDMS柔性膜的受力形变是实现其与不同衬底紧密贴合的基础，针对不同的目标衬底，仅需要更换对应的衬底微调系统盖板，结合三维位移机械系统，即可实现一维和二维材料的通用定点转移。该方法避免了转移过程中的真空吸附及衬底加热等严格条件，降低了材料的定点转移难度并提高了其稳定性和通用性。此外该方法也可实现低维材料同质结或其它垂直结构的构建，从而极大提高低维材料结构的丰富性。