Printable HTM-free (HTM = hole -transporting material) mesoporous carbon -based perovskite solar cells (C-PSCs) are one of the most promising technologies. In this study, a high -quality chlorinated mesoscopic TiO2 (m-TiO2) film was obtained by hydrochloric acid (HCl) wet chemical process and applied in C-PSCs based on TiO2/ZrO2/ (5-AVA)x(MA)1-xPbI3/C structures. Experimental results show that the PCE of chlorinated m-TiO2 C-PSCs greatly improved. Based on (5-AVA)x(MA)1-xPbI3, C-PSCs with TiO2 ETL treated with HCl aqueous solution achieved an average photovoltaic conversion efficiency of 9.36 %, which is an increase of 7.96 % in comparison with the efficiency of the device using unmodified TiO2 ETL, while the Voc and the Jsc were increased by 3.63 % and 2.63 %, respectively. In a 30 -day aging test, C-PSCs based on (5-AVA)x(MA)1-xPbI3 and TiO2-HCl 1 exhibited excellent stability under ambient air conditions.

Inactive gas (N2 or Ar) and oxygen scavenger (Fe2+ or Cu+) are used for the synthesis of silver nanowires (AgNWs) with thin diameter (< 30 nm) and high aspect ratio (> 1000), but the yield is always low. Due to the oxidative etching, oxygen largely influences silver nanostructures not only in the nucleation process but also in the growth period. Herein, we systematically studied AgNW synthesis under the condition of an atmosphere with different oxygen contents (O2, air, and N2). We separated the formation of Ag-twinned seeds and nanoparticles in the incubation and the elongation of AgNWs in the growth, which are both sensitive to the oxygen content. AgNWs with 28.5 nm diameter, 2500 aspect ratio, and 91% yield were obtained when the sample was protected in N2 (incubation) and refluxed with air (growth), resulting in a conductive film with a sheet resistance of 48 Ω/sq at a transmittance of 97.0%, comparable to that of ITO. The growth mechanism of such high-quality AgNWs was discussed.

Flexible electronic devices, sensing human movement and monitoring physiological signals, might be useful for performing research in the area of intelligent detection. Gallium (Ga), a liquid metal (LM), is often used as a soft conductive material in the form of droplets because of its unique properties. Herein, a liquid metal-induced ionogel is synthesized by polymerizing acrylic acid (AA) with the existence of poly(diallyldimethylammonium chloride) (PDDA) and Ga droplets. In the system, the free radical formed from Ga oxidation process initiates the polymerization of AA. Meanwhile, the Ga3+ produced by Ga oxidation forms a coordination with the -COO- on PAA chains. The coordination crosslinking sites create slip when the gel is exposed to external force, increasing the stretchability (5000 %) of the ionogel. When the Ga droplets are completely oxidized to Ga3+, the gel changes from silvery gray to transparent (80 %). In addition, the ionic liquids and the electrostatic interactions within the network enable the resultant ionogel anti-dehydration (98 %) and self-healing performances in a wide temperature range (-20 similar to 20 degrees C). The liquid metal-induced ionogel can be assembled into a flexible sensor with adequate sensitivity, rapid response time (240 ms), and cyclic stability, demonstrating human movement patterns with accuracy to keep track of physiological signs.

The schematic of the effects of chlorinated graphite (C–Cl) on the interface of carbon and perovskite and the energy level alignment.

A two-step swelling method synthesized CH 3 NH 3 PbX 3 perovskite, which is stable under high moisture, oxygen plasma treatment, and extreme acid-alkali environment.

We have successfully fabricated transparent conductive mesoporous indium tin oxide (TCM-ITO) films by a screen-printing method. The TCM-ITO films possess approximately 22 nm mesopores and obtain electrical conductivity up to 14.96 S/cm by adjusting the mass ratio of cubic-shaped ITO nanoparticles to ethyl cellulose (EC) and precisely controlling the annealing process. The regulation mechanism of EC and the heat-induced recrystallization process of ITO nanoparticles are elaborated. The internal kinetic processes of the films based on different surface states are analysed, and an extensible impedance model is established.

In recent years, many research groups have synthesized ultra-thin silver nanowires (AgNWs) with diameters below 30 nm by employing Cl− and Br− simultaneously in the polyol process. However, the yield of AgNWs in this method was low, due to the production of Ag nanoparticles (AgNPs) as an unwanted byproduct, especially in the case of high Br− concentration. Here, we investigated the roles of Cl− and Br− in the preparation of AgNWs and then synthesized high aspect ratio (up to 2100) AgNWs in high yield (>85% AgNWs) using a Cl− and Br− co-mediated method. We found that multiply-twinned particles (MTPs) with different critical sizes were formed and grew into AgNWs, accompanied by a small and large amount of AgNPs for the NaCl and NaBr additives, respectively. For the first time, we propose that the growth of AgNWs of different diameters and yields can be understood based on the electron trap distribution (ETD) of the silver halide crystals. For the case of Cl− and Br− co-additives, a mixed silver halide crystal of AgBr1−xClx was formed, rather than the AgBr/AgCl mixture reported previously. In this type of crystal, the ETD is uniform, which is beneficial for the synthesis of AgNWs with small diameter (30~40 nm) and high aspect ratio. AgNW transparent electrodes were prepared in air by rod coating. A sheet resistance of 48 Ω/sq and transmittance of 95% at 550 nm were obtained without any post-treatment.