A systematic strategy for effectively engineering the charge extraction in inverted structured perovskite solar cells based on CH₃NH₃PbI_3−xCl_xis provided. An optimized power conversion efficiency of 20.5% is realized.

The unique properties and structures of metal halide perovskite materials desired for a variety of photocatalytic applications in water splitting, CO ₂ reduction, pollutant degradation, and organic synthesis.

Plasmonic nanolasers have ushered in a paradigm of deep sub-wavelength coherent optical sources with ultrafast dynamics that exploit the strong confinement capabilities of metals. Although these devices are usually associated with higher thresholds due to absorption in metals, the high gain inorganic II–VI and III–V semiconductor materials have allowed the realization of plasmonic nanolasers operating under ambient conditions. In this work, we introduce single-crystalline lead halide perovskite (CH₃NH₃PbI₃) nanowires as an organic–inorganic semiconducting gain material to the plasmonic laser community. We demonstrate plasmonic laser action using a hybrid geometry whereby the perovskite nanowires are placed on a silver substrate with an insulating spacer layer. We report relatively low threshold operation under ambient conditions (13.5 μJ cm⁻²), and the devices work well even at temperatures up to 43.6 °C. The demonstration highlights the high optical gain achievable in perovskite materials and thus provides a solution to high gain materials for plasmonic devices.

Though power conversion efficiencies of perovskite solar cells of over 21% have been reported, the degradation of the performance of these cells in the presence of moisture still inhibits the commercialization of these otherwise promising devices. Herein, we decided to utilize the moisture sensitivity of perovskite materials and fabricate a moisture detector based on high-quality CH₃NH₃PbI_3−xCl_x nanosheet arrays. The resulting devices present a high sensitivity towards humidity with device resistance significantly dropping from 1.28 × 10⁸ Ω at 30% relative humidity (RH) to 7.39 × 10⁴ Ω at 90% RH and a response even faster than that of the commercial psychrometer. This response was even steeper than those of commercial psychrometers. Moreover, our device showed good reversibility and impressive specificity. Thus, the humidity sensitivity of perovskites, while disadvantageous for solar cell applications, was found to be quite applicable in a new field.

Dispersive SnS₂ colloidal quantum dots have been synthesized via hot-injection method. Hybrid photovoltaic devices based on blends of a conjugated polymer poly[2-methoxy-5-(3",7"dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) as electron donor and crystalline SnS₂ quantum dots as electron acceptor have been studied. Photoluminescence measurement has been performed to study the surfactant effect on the excitons splitting process. The photocurrent of solar cells with the hybrid depends greatly on the ligands exchange as well as the device heat treatment. AFM characterization has demonstrated morphology changes happening upon surfactant replacement and annealing, which can explain the performance variation of hybrid solar cells.