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.

Metallic nanoparticles array is served as a promising way to realize on-chip lasers. To achieve high-performance lasers, efficient gain media are also critical. Here, we present a pressure-assisted process for CsPbBr3 quantum dots to realize a plasmonic lattice laser.