Aromatic Heterocyclic Organic Spacer Cation-Assisted Growth of Large-Grain-Size 2DRP Perovskite Film for Enhanced Solar Cell Performance

Organic spacer cations play an important role in the aggregation of two-dimensional Ruddlesden–Popper (2DRP) L′2Ln–1BnX3n+1 perovskite precursors. Therefore, it is necessary to study how mixed A′ spacer cations affect the aggregation behavior of precursors and the carrier transport properties of 2DRP films. Herein, a novel spacer cation 4-pyridinylmethylammonium (PyA) is introduced to prepare a new mixed spacer cation 2DRP (BA1–xPyAx)2MA3Pb4I13 perovskite. The incorporation of PyA suppresses the precursor aggregation and reduces the transformation energy of the sol–gel to the directional three-dimensional phase, leading to the formation of large-grain-size 2DRP perovskite films. The PyA-based 2DRP perovskite exhibits efficient carrier transport owing to fewer defects and suppressed nonradiative recombination. Thus, the champion efficiency of 13.01% is achieved for BA- and PyA-based devices. The unencapsulated PyA-based devices maintain 98% of their initial efficiency after storage under nitrogen atmosphere for 1200 h. This work paves the way for preparing a large-grain-size 2DRP perovskite by suppressing precursor aggregation

In Situ versus ex Situ Assembly of Aqueous-Based Thioacid Capped CdSe Nanocrystals within Mesoporous TiO₂ Films for Quantum Dot Sensitized Solar Cells

We report a straightforward in situ deposition method to directly assemble aqueous thioglycolic acid capped CdSe colloidal quantum dots within mesoporous TiO₂ thin films by a low-temperature hydrothermal route. This approach integrates linker assisted adsorption and colloidal quantum dot synthesis in a single step due to the use of thioglycolic acid as the capping agent for the quantum dots and tethering agent for the TiO₂. It permits high loading and uniform distribution of colloidal quantum dots within mesoporous TiO₂ electrodes with a greatly improved photovoltaic performance as quantum dot sensitized solar cells, reaching efficiencies as high as 2.2% under one sun illumination conditions after ZnS treatment, compared to the ex situ assembly technique of adsorption of presynthesized semiconductor nanocrystals

Flow diagram of study identification.

<p>Flow diagram of study identification.</p

Forest plot of cancer metastasis risk associated with <i>MMP7 (−181) A>G</i>.

<p>A fixed-effects model was used. A indicates the result under the dominant model (<i>GG+AG</i> vs. <i>AA</i>). B indicates the result under the recessive model (<i>GG</i> vs. <i>AG+AA</i>). The <i>squares</i> and <i>horizontal line</i> represent the study-specific OR and 95% CI. The <i>diamond</i> represents the pooled results of OR and 95% CI.</p

Forest plot of cancer metastasis risk associated with <i>MMP1 (−1607) 1G>2G</i> under the recessive model.

<p>A random-effects model was used. The <i>squares</i> and <i>horizontal line</i> represent the study-specific OR and 95% CI. The <i>diamond</i> represents the pooled results of OR and 95% CI.</p

Stratified analysis of MMP polymorphisms on cancer metastasis.

a<p>Number of comparisons.</p>b<p><i>P</i> value for <i>Q</i> test.</p>c<p>Random effect model was used.</p

Small Molecule-Modified Hole Transport Layer Targeting Low Turn-On-Voltage, Bright, and Efficient Full-Color Quantum Dot Light Emitting Diodes

For an organic–inorganic hybrid quantum dot light-emitting diode (QD-LED), enhancing hole injection into the emitter for charge balance is a priority to achieve efficient device performance. Aiming at this, we employ <i>N</i>,<i>N</i>′-bis­(3-methylphenyl)-<i>N</i>,<i>N</i>′-bis­(phenyl)­benzidine (TPD) as the additional hole transport material which was mixed with poly­(9-vinylcarbazole) (PVK) to form a composite hole transport layer (HTL) or was employed to construct a TPD/PVK bilayer structure. Enabled by this TPD modification, the green QD-LED (at a wavelength of 515 nm) exhibits a subband gap turn-on voltage of 2.3 V and a highest luminance up to 56 157 cd/m². Meanwhile, such TPD modification is also beneficial to acquire efficient blue and red QD-LEDs. In particular, the external quantum efficiencies (EQEs) for these optimized full-color QD-LEDs are 8.62, 9.22, and 13.40%, which are 3–4 times higher than those of their pure PVK-based counterparts. Revealed by the electrochemical impedance spectroscopy, the improved electroluminescent efficiency is ascribable to the reductions of recombination resistance and charge-transfer resistance. The prepared QD-LEDs surpass the EQE values achieved in previous reports, considering devices with small-molecule-modified HTLs. This work offers a general but simple and very effective approach to realize the low turn-on-voltage, bright, and efficient full-color QD-LEDs via this solution-processable HTL modification

Comparison of genotype distribution of MMP polymorphisms between cancer metastasis positive and negative subjects.

a<p>represents the number of AA+AB genotype,</p>b<p>represents the number of BB+AB genotype (A represents the major allele, B represents the minor allele),</p>c<p>NSCLC represents non-small cell lung carcinoma,</p>d<p>ESCC represents esophageal squamous cell carcinoma.</p>e<p>GCA represents gastric cardiac adenocarcinoma.</p

Forest plot of cancer metastasis risk associated with <i>MMP3 (−1171) 5A>6A</i>.

<p>A fixed-effects model was used. A indicates the result under the dominant model (<i>6A/6A+5A/6A</i> vs. <i>5A/5A</i>). B indicates the result under the recessive model (<i>6A/6A</i> vs. <i>5A/5A+5A/6A</i>). The <i>squares</i> and <i>horizontal line</i> represent the study-specific OR and 95% CI. The <i>diamond</i> represents the pooled results of OR and 95% CI.</p

Forest plot of cancer metastasis risk associated with <i>MMP9 (−1562) C>T</i> under the dominant model.

<p>A fixed-effects model was used. The <i>squares</i> and <i>horizontal line</i> represent the study-specific OR and 95% CI. The <i>diamond</i> represents the pooled results of OR and 95% CI.</p