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MAPbBr3 (MA: CH3NH3+) undergoes surface degradation under dark and vacuum conditions that leads to the formation of surface PbBr2 species.

( 99m ) Tc-UBI (29-41) accumulation directly correlates with the number of viable bacteria. This infection localization agent can be utilized for monitoring efficacy and duration of antibiotic treatment.

In the rapidly progressing field of organometal halide perovskites, the dimensional reduction can open up new opportunities for device applications. Herein, taking the recently synthesized trimethylsulfonium lead triiodide (CH 3 ) 3 SPbI 3 perovskite as a representative example, first-principles calculations are carried out and the nanostructuring and device application of halide perovskite nanowires are studied. It is found that the 1D (CH 3 ) 3 SPbI 3 structure is structurally stable, and the electronic structures of higherdimensional forms are robustly determined at the 1D level. Remarkably, due to the face-sharing [PbI 6 ] octahedral atomic structure, the organic ligandremoved 1D PbI 3 frameworks are also found to be stable. Moreover, the PbI 3 columns avoid the Peierls distortion and assume a semimetallic character, contradicting the conventional assumption of semiconducting metal-halogen inorganic frameworks. Adopting the bundled nanowire junctions consisting of (CH 3 ) 3 SPbI 3 channels with sub-5 nm dimensions sandwiched between PbI 3 electrodes, high current densities and large room-temperature negative differential resistance (NDR) are finally obtained. It will be emphasized that the NDR originates from the combination of the near-Ohmic character of PbI 3 -(CH 3 ) 3 SPbI 3 contacts and a novel NDR mechanism that involves the quantum-mechanical hybridization between channel and electrode states. This work demonstrates the great potential of low-dimensional hybrid perovskites toward advanced electronic devices beyond actively pursued photonic applications.

Atomistic characterization of surface termination and the corresponding mechanical properties of single-crystal methylammonium lead tribromide (MAPbBr 3 ) are performed using combined atomic force microscopy (AFM) measurements and density functional theory (DFT) calculations. A clean MAPbBr 3 surface is obtained by in situ cleavage in ultrahigh vacuum at room temperature, and the subsequent AFM measurements of the as-cleaved MAPbBr 3 exhibit the coexistence of two different surface terrace types with step height differences corresponding to about half the thickness of a PbI 6 octahedron layer. Concurrent friction force microscopy measurements show that the two surfaces result in two distinct friction values. Based on DFT calculations, we attribute the higher-friction and lower-friction surfaces to MABrterminated flat and PbBr 2 -terminated vacant surface terminations, respectively. The calculated electronic band structures of the various MABr-and PbBr 2 -terminated surfaces show that the midgap states are absent, revealing the defect-tolerant nature of the ideal single-crystal MAPbBr 3 surfaces.

Perovskite solar cells (PSC) have shown a rapid increase in efficiency than other photovoltaic technology. Despite its success in terms of efficiency, this technology is inundated with numerous challenges hindering the progress towards commercial viability. The crucial one is the anomalous hysteresis observed in the photocurrent density‐voltage (J−V) response in PSC. The hysteresis phenomenon in the solar cell presents a challenge for determining the accurate power conversion efficiency of the device. A detailed investigation of the fundamental origin of hysteresis behavior in the device and its associated mechanisms is highly crucial. Though numerous theories have been proposed to explain the causes of hysteresis, its origin includes slow transient capacitive current, trapping, and de‐trapping process, ion migrations, and ferroelectric polarization. The remaining issues and future research required toward the understanding of hysteresis in PSC device is also discussed.

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Perovskite solar cells (PSCs) are broadly assembled in two ways; regular (n-i-p) and inverted (p–i–n) structures. Inverted PSCs architecture have attracted attention due to their consistent operational stability and low...