Lead halide perovskites exhibit extraordinary optoelectronic performances and are being considered as a promising medium for high‐quality photonic devices such as single‐mode lasers. However, for perovskite‐based single‐mode lasers to become practical, fabrication and integration on a chip via the standard top‐down lithography process are strongly desired. The chief bottleneck to achieving lithography of perovskites lies in their reactivity to chemicals used for lithography as illustrated by issues of instability, surface roughness, and internal defects with the fabricated structures. The realization of lithographic perovskite single‐mode lasers in large areas remains a challenge. In this work, a self‐healing lithographic patterning technique using perovskite CsPbBr3 nanocrystals is demonstrated to realize high‐quality and high‐crystallinity single‐mode laser arrays. The self‐healing process is compatible with the standard lithography process and greatly improves the quality of lithographic laser cavities. A single‐mode microdisk laser array is demonstrated with a low threshold of 3.8 µJ cm−2. Moreover, the control of the lasing wavelength is made possible over a range of up to 6.4 nm by precise fabrication of the laser cavities. This work presents a general and promising strategy for standard top‐down lithography fabrication of high‐quality perovskite devices and enables research on large‐area perovskite‐based integrated optoelectronic circuits.

Plasmonic nanolasers provide a valuable opportunity for expanding sub‐wavelength applications. Due to the potential of on‐chip integration, semiconductor nanowire (NW)‐based plasmonic nanolasers that support the waveguide mode attract a high level of interest. To date, perovskite quantum dots (QDs) based plasmonic lasers, especially nanolasers that support plasmonic‐waveguide mode, are still a challenge and remain unexplored. Here, metallic NW coupled CsPbBr3 QDs plasmonic‐waveguide lasers are reported. By embedding Ag NWs in QDs film, an evolution from amplified spontaneous emission with a full width at half maximum (FWHM) of 6.6 nm to localized surface plasmon resonance (LSPR) supported random lasing is observed. When the pump light is focused on a single Ag NW, a QD‐NW coupled plasmonic‐waveguide laser with a much narrower emission peak (FWHM = 0.4 nm) is realized on a single Ag NW with the uniform polyvinylpyrrolidone layer. The QDs serve as the gain medium while the Ag NW serves as a resonant cavity and propagating plasmonic lasing modes. Furthermore, by pumping two Ag NWs with different directions, a dual‐wavelength lasing switch is realized. The demonstration of metallic NW coupled QDs plasmonic nanolaser would provide an alternative approach for ultrasmall light sources as well as fundamental studies of light matter interactions.

Perovskite materials prepared in the form of solution-processed nanocrystals and used in top-down fabrication techniques are very attractive to develop low-cost and high-quality integrated optoelectronic circuits. Particularly, integrated miniaturized coherent...

Solution‐process perovskite quantum dots (QDs) are promising materials to be utilized in photovoltaics and photonics with their superior optical properties. Advancements in top‐down nanofabrication for perovskite are thus important for practical photonic and plasmonic devices. However, different from the chemically synthesized nano/micro‐structures that show high quality and low surface roughness, the perovskite QD thin film prepared by spin‐coating or the drop‐casting process shows a large roughness and inhomogeneity. Low‐roughness and low‐optical loss perovskite QD thin film is highly desired for photonic and optoelectronic devices. Here, this work presents a pressure‐assisted ligand engineering/recrystallization process for high‐quality and well‐thickness controlled CsPbBr3 QD film and demonstrates a low‐threshold and single‐mode plasmonic lattice laser. A recrystallization process is proposed to prepare the QD film with a low roughness (RMS = 1.3 nm) and small thickness (100 nm). Due to the low scattering loss and strong interaction between gain media and plasmonic nanoparticles, a low lasing threshold of 16.9 µJ cm−2 is achieved. It is believed that this work is not only important to the plasmonic laser field but also provides a promising and general nanofabrication method of solution‐processed QDs for various photonic and plasmonic devices.

By combining surface-enhanced Raman spectroscopy together with resonance Raman effects in the deep-UV region, ultra-sensitive and selective molecule detection can be achieved by deep-UV surface-enhanced resonance Raman spectroscopy (SERRS). Here, we report a deep-UV plasmonic nano-eggs structure consisting of elongated Al nanoparticles on black Si (BSi) for use in deep-UV SERRS characterization of biomolecules. The Al/BSi nano-eggs structure can be easily fabricated over a large area via conventional techniques including inductively coupled-plasma reactive ion etching on a Si substrate and Al sputtering without the need for accurate thickness control. A home-built deep-UV SERRS setup with the excitation wavelength of 266 nm is used to characterize adenine deposited on Al/BSi nano-eggs structures. High-intensity and reproducible Raman signals for adenine are obtained. A low-cost and easy-to-fabricate Al/BSi nano-eggs structure provides a convenient means to achieve deep-UV SERRS characterization, and it is thought to be beneficial for the development of ultra-sensitive molecule detection schemes.