Large‐Area Lasing and Multicolor Perovskite Quantum Dot Patterns

Abstract

We report a novel orthogonal lithography fabrication of patterned inorganic perovskite CsPbX 3 (X= Cl, Br, I) quantum dot (QD) arrays which cannot be patterned with traditional approaches. This approach involves a combination of fluorinated polymer and solvent to resolve issues of polar-non-polar solvent constraints thus enabling the fabrication of complex patterns with high optical gain and bright and multicolor emission. We utilized this approach to fabricate high-resolution large-area arrays of microdisk lasers and milticolor (binary-and ternary-emission) pixels. The optical cavity modes of CsPbBr 3 QD microdisk lasers were readily controlled by tuning the disk size, where the mode spacing decreases while the number of modes increases with increasing disk diameter. Finally, we demonstrated the versatility of our approach for the integration of environmentally-sensitive QDs with different emission signatures and composition on the same chip, while achieving high density, highresolution large-area QD arrays with multicolor pixels.

Halide Perovskite Nanocrystals for Next‐Generation Optoelectronics

“…To this end, Lin et al introduced a fluorinated polymer‐based photolithography method, where the nonsolubility of the CsPbBr 3 NCs in fluorinated solvents was used in lift‐off patterning on arbitrary substrates. Microdisk lasers made with this technique showed lasing thresholds of 200 µJ cm −2 , when excited by 450 nm, 7 ns pulsed laser source . In contrast to the accurately patterned lasers, in random lasers the optical feedback comes from loops formed by random scattering .…”

“…Microdisk lasers made with this technique showed lasing thresholds of 200 µJ cm −2 , when excited by 450 nm, 7 ns pulsed laser source . In contrast to the accurately patterned lasers, in random lasers the optical feedback comes from loops formed by random scattering . Li et al used PNCs anchored onto silica nanospheres to create luminescent PNC–SiO 2 composite films that show random lasing with thresholds down to 40 µJ cm −2 when optically pumped with 100 fs, 400 nm pulses .…”

Recent Progress in Metal Halide Perovskite Micro‐ and Nanolasers

“…These results gave prominence to the practical lasers in CsPbX 3 perovskite NCs and illustrated the probability of independent adjustment of cavity and gain materials for the VCSELs, which represented a huge advancement in laser sources based on the favorable CsPbX 3 perovskite NCs. Furthermore, the realization of QDs lasing by using the versatility method including photolithography and others are possible . Addition to one‐photon pumped lasing of QDs, the large multiphoton absorption and PL in CsPbBr 3 NCs, in which large two‐photon absorption (2PA) cross‐section up to ≈1.2 × 10 5 GM was determined in 9 nm CsPbBr 3 perovskite NCs, makes perovskite QDs being considered as a prospective medium to obtain frequency upconversion lasing.…”

Composite Structures with Emissive Quantum Dots for Light Enhancement

“…b) PL images of green red Cd‐based QDs microdisks (top left) and PVK QDs QR code (bottom left) and RGB pixels (right). Reproduced with permission . Copyright 2017, Wiley‐VCH; 2018, Wiley‐VCH.…”

“…A photolithography patterning process was applied for both Cd‐based QDs (with functionalized ligands as crosslinkers) and perovskite QDs (with orthogonal photoresist) (Figure b). Notably, the latter photolithography process has successfully fabricated various patterns including RGB pixelated patterns, as well as high‐resolution lasing cavities with a quality factor of 500–600.…”