Highly reproducible organometallic-halide-perovskite-based devices are fabricated by a manufacturing process, which is demonstrated. Various shapes that are hard to synthesize directly are fabricated, and many unique properties are achieved.The fabrication procedure is utilized to create a photodetector and the detection sensitivity is significantly improved. The results will bring revolutionary advancement to the future of lead-halide-perovskite-based optoelectronic devices.

Very recently, perovskite based microdisk lasers have attracted considerable research attention. However, most of the researches are focused on the lasing spectra in bottom-up synthesized microdisks with regular shapes. The directionality, which is also essential for practical applications, has not been explored. Here we demonstrate unidirectional lasing emissions from perovskite microdisks for the first time. We synthesized the rectangle-shaped microdisks connected with straight waveguides and studied the lasing characteristics, where unidirectional emissions along the waveguides have been observed. Numerical calculations reveal that the unidirectional emissions are formed by the breaking of total internal reflections at the joints between waveguides and microdisks. Since waveguides are compatible with other photonic elements, we believe that our finding will be essential for the applications of perovskite microdisks in integrated photonic circuits and networks.

Lead halide perovskites based microlasers have recently shown their potential in nanophotonics. However, up to now, all of the perovskite microlasers are static and cannot be dynamically tuned in use. Herein, we demonstrate a robust mechanism to realize the all-optical control of perovskite microlasers. In lead halide perovskite microrods, deterministic mode switching takes place as the external excitation is increased: the onset of a new lasing mode switches off the initial one via a negative power slope, while the main laser characteristics are well kept. This mode switching is reversible with the excitation and has been explained via cross-gain saturation. The modal interaction induced mode switching does not rely on sophisticated cavity designs and is generic in a series of microlasers. The switching time is faster than 70 ps, extending perovskite microlasers to previously inaccessible areas, e.g., optical memory, flip-flop, and ultrafast switches etc.

Solution‐processed lead halide perovskites have shown good applicability in both solar cells and microlasers. Very recently, the nonlinear properties of perovskites have attracted considerable research attention. Second harmonic generation and two‐photon absorption have been successfully demonstrated. However, perovskite devices based on these nonlinear properties, such as micro‐ and nanolasers have thus far not been fabricated. Here we demonstrate two‐photon pumped microlasers from CH3NH3PbBr3 perovskite microwires. These CH3NH3PbBr3 perovskite microwires are synthesized through a one‐step solution precipitation method and dispersed on a glass substrate. Under optical excitation at 800 nm, two‐photon pumped lasing action with periodic peaks is successfully observed at around 546 nm. The obtained quality (Q) factors of the two‐photon pumped microlasers are around 682, and the corresponding thresholds are about 674 µJ cm‐2. Both the Q factors and thresholds are comparable to conventional whispering‐gallery modes in two‐dimensional polygon microplates. This work is the first demonstration of two‐photon pumped microlasers in CH3NH3PbBr3 perovskite microwires. We believe our finding will significantly expand the application of perovskites in low‐cost nonlinear optical devices, such as optical limiters, optical switches, and biomedical imaging devices.

Recently, due to broad wavelength tunability and high material stability, cesium lead halide perovskite nanorods have been intensively studied as potential candidates for microlasers and photodetectors. However, the current CsPbX3 perovskite nanorods can only support low quality (Q) Fabry–Perot lasers and the response time of CsPbX3 nanorod photodetector is extremely long. Here, CsPbBr3 microrods with larger cross‐sectional sizes and almost uniform aspect ratio are successfully synthesized with a solution processed one‐step precipitation method and their applications in microlasers and photodetectors are reported. Due to the larger cross‐sectional size, whispering‐gallery‐mode lasers can be formed in the transverse plane of CsPbBr3 microrod under both of one‐photon and two‐photon excitation. The highest Q factor can reach around 7000. Besides, the synthesized CsPbBr3 perovskite lasers have shown much better photostability and thermal stability. The single‐crystalline CsPbBr3 microrods also provide a stable platform for photodetectors. The rise and decay time of CsPbBr3 microrod based photodetectors are around 8 ms, which are almost two orders of magnitude smaller than the previously reported CsPbX3 microrod photodetector. Such findings can pave new route on all‐inorganic CsPbX3 based optoelectronic devices.

The realization of high density and highly uniform nanolaser arrays in lead halide perovskite is quite challenging, especially on silicon. Herein, we demonstrate a simple way to form lead halide nanolaser array on silicon chip with high density and uniform lasing wavelengths. By positioning a perovskite microwire onto a silicon grating, only the suspended parts can hold high quality (Q) resonances and generate laser emissions. As the perovskite microwire is periodically segmented by the silicon grating, the transverse lasers are divided into a periodic nanolaser array and the lasing wavelengths from different subunits are almost the same. The transverse laser has been observed in an air gap as narrow as 420 nm, increasing the density of nanolasers to about 1250 per millimeter (800 nm period in experiment). We believe this research shall shed light on the development of perovskite microlaser and nanolaser arrays on silicon and their applications.

All-inorganic cesium lead halide perovskites hold great promise for the development of next-generation optoelectronics. However, it remains unexplored how the energetic ions will impact CsPbX3, which may largely limit the application potentials. In this work, we for the first time investigate the interaction between the CsPbX3 and high-energy gallium ions in a broad range of ion doses provided by a focused ion beam (FIB) system. We found that the optical properties of CsPbX3 are highly sensitive to the energetic Ga + ions due to the relatively vulnerable ionic bonding. Specifically, even low-dose Ga + irradiation (~110 15 ions/cm 2 ) can lead to more than one-order-of-magnitude reduction in the photoluminescence (PL) intensity, whcih can be attributed to the combined effects of the formation of vacancy/interstitial defects, generation of metallic Pb-related nonradiative recombination centers and crystal-to-amorphization transition. With the increase of ion dose (~10 17 ions/cm 2 ), the morphology of CsPbX3 can be dramatically altered due to the ion sputtering effect. We demonstrate that both low-and high-dose FIB treatment can be important for realizing the application prospects of CsPbX3 in optical security protection and system-on-a-chip compatible microlasers. Our results offer significant information about the ion impacts on CsPbX3 and offer an enabling tool to manipulate the emission and lasing from CsPbX3, which could push ahead the potential of CsPbX3 in photonics and optoelectronics.

The synthesized perovskites are randomly distributed and their optical properties are fixed after synthesis. Here we demonstrate the tailoring of lasing properties of perovskite microwire via micromanipulation. One microwire has been lifted by a tungsten probe and repositioned on a nearby perovskite microplate with one end suspended in air. Consequently, the conventional Fabry-Perot lasers are completely suppressed and a single laser peak has been observed. The numerical calculations reveal that the single-mode laser is formed by the whispering-gallery mode in the transverse plane of microwire. Our research provides a simple way to tailor the properties of microwire postsynthesis.