CsPbBr and CsAgBiBr Composite Thick Films with Potential Photodetector Applications.

This paper investigates the optoelectronic properties of CsPbBr, a lead-based perovskite, and CsAgBiBr, a lead-free double perovskite, in composite thick films synthesized using mechanochemical and hot press methods, with poly(butyl methacrylate) as the matrix. Comprehensive characterization was conducted, including X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-visible spectroscopy (UV-Vis), and photoluminescence (PL). Results indicate that the polymer matrix does not significantly impact the crystalline structure of the perovskites but has a direct impact on the grain size and surface area, enhancing the interfacial charge transfer of the composites.

Photoinduced Self-Gating of Perovskite Photovoltaic Cells in Ionic Liquid.

We demonstrate that the power conversion efficiency (PCE), photocurrent, and fill factor (FF) of perovskite solar cells (PSC) can be significantly improved by the photoinduced self-gating in ionic liquids (ILs) via n-doping of the carbon nanotube (CNT) top electrode on the fullerene electron transport layer (ETL). CNTs, graphene, and other carbon electrodes have been proven to be stable electrodes for PSC, but efficiency was not high. We have previously shown that the performance of PSCs with CNT electrodes can be improved by IL gating with gate voltage () applied from an external power source.

Connecting the Dots from Professional Development to Student Learning.

Following professional development (PD), implementation of contemporary topics into high school biology requires teachers to make critical decisions regarding integration of novel content into existing course scope and sequence. Often exciting topics, such as neuroscience, do not perfectly align with standards. Despite commitment to enacting what was learned in the PD, teachers must adapt novel content to their perceptions of good teaching, local context, prior knowledge of their students, and state and district expectations.

Room-Temperature Continuous-Wave Operation of Organometal Halide Perovskite Lasers.

Solution-processed organic-inorganic lead halide perovskites have recently emerged as promising gain media for tunable semiconductor lasers. However, optically pumped continuous-wave lasing at room temperature, a prerequisite for a laser diode, has not been realized so far. Here, we report lasing action in a surface-emitting distributed feedback methylammonium lead iodide (MAPbI) perovskite laser on a silicon substrate at room temperature under continuous-wave optical pumping.

Continuous-wave operation in directly patterned perovskite distributed feedback light source at room temperature.

We report a directly patterned perovskite distributed feedback (DFB) resonator and show narrow amplified spontaneous emission (ASE) at pump powers as low as 0.1  W/cm under continuous-wave (CW) optical pumping conditions at room temperature. Compared to the pristine thin film photoluminescence spectrum, a 16-fold reduction in emission linewidth in the MAPbI DFB cavity was observed.

Nanoimprinted perovskite metasurface for enhanced photoluminescence.

Recently, solution-processed hybrid halide perovskite has emerged as promising materials for advanced optoelectronic devices such as photovoltaics, photodetectors, light emitting diodes and lasers. In the mean time, all-dielectric metasurfaces with high-index materials have attracted attention due to their low-loss and high-efficient optical resonances. Because of its tunable by composition band gap in the visible frequencies, organolead halide perovskite could serve as a powerful platform for realizing high-index, low-loss metasurfaces.

Resonant silicon nanoparticles for enhancement of light absorption and photoluminescence from hybrid perovskite films and metasurfaces.

Recently, hybrid halide perovskites have emerged as one of the most promising types of materials for thin-film photovoltaic and light-emitting devices because of their low-cost and potential for high efficiency. Further boosting their performance without detrimentally increasing the complexity of the architecture is critically important for commercialization. Despite a number of plasmonic nanoparticle based designs having been proposed for solar cell improvement, inherent optical losses of the nanoparticles reduce photoluminescence from perovskites.

Nanoimprinted Perovskite Nanograting Photodetector with Improved Efficiency.

Recently, organolead halide-based perovskites have emerged as promising materials for optoelectronic applications, particularly for photovoltaics, photodetectors, and lasing, with low cost and high performance. Meanwhile, nanoscale photodetectors have attracted tremendous attention toward realizing miniaturized optoelectronic systems, as they offer high sensitivity, ultrafast response, and the capability to detect beyond the diffraction limit. Here we report high-performance nanoscale-patterned perovskite photodetectors implemented by nanoimprint lithography (NIL).

Extended carrier lifetimes and diffusion in hybrid perovskites revealed by Hall effect and photoconductivity measurements.

Impressive performance of hybrid perovskite solar cells reported in recent years still awaits a comprehensive understanding of its microscopic origins. In this work, the intrinsic Hall mobility and photocarrier recombination coefficient are directly measured in these materials in steady-state transport studies. The results show that electron-hole recombination and carrier trapping rates in hybrid perovskites are very low.