Improving the triple-cation perovskite solar cells by two-step deposition methods with perovskite seeds

As of recent years, triple-cation perovskite solar cells have received immense attention due to its superior efficiency and better stability comparing to the classic single-cation perovskite solar cells such as MAPbI3 or FAPbI3. A triple-cation perovskite layer which has been used most recently is cesium-containing FAPbI3-based perovskite. One of decent approaches to fabricate the layer is spin-coating technique by using two-step deposition process in which mixed lead-halide and CsI precursor is firstly spin-coated onto a substrate, then organic cation solution is deposited on the lead-halide layer. In this work, the results show that the performance of the devices from this process is lower than expected that could be due to difficulty of cesium ion incorporation as a stabilizer for FAPbI3-based perovskite. Perovskite seeding growth is introduced to solve the problem where the process is slightly modified from conventional two-step deposition methods by adding small amount of perovskite seed precursor into PbI2 solution. The concentration of the perovskite seed in PbI2 solution was varied for 0, 7, 14 and 20% v/v. The highest average efficiency of 11.9% was obtained from 7% v/v seeding concentration. Furthermore, the device performance could be improved by using proper amount of chlorobenzene (CB) as an anti-solvent. The highest efficiency of 18.4% was achieved by using 30 µl of chlorobenzene.

Cesium in Biology, Pancreatic Cancer, and Controversy in High and Low Radiation Exposure Damage—Scientific, Environmental, Geopolitical, and Economic Aspects

Radionuclide contamination in terrestrial ecosystems has reached a dangerous level. The major artificial radionuclide present in the environment is cesium-137 (137-Cs). In humans, animals, and plants cesium ion (Cs+) behaves like potassium ion (K+) and it is localized mainly inside the cells. Pancreas and salivary glands secrete Cs in the intestine thus eliminating about 14% of ingested Cs with the feces, the remaining 86% is eliminated by the kidney with the urine. Ingested radiocesium can also cause in humans several cases of pancreatitis with secondary diabetes (type 3c), which are both on the rise in the world. The Author studied the correlation between the geographical map of mortality from pancreatic cancer (PC) and the map of nuclear plant accidents, atomic bomb testing, and radioactive fallout. The worldwide death rate of PC is increasing, but the exact cause is still not known. Published data in medical literature at World, European and Italian levels are reviewed and compared. 137-Cs, with a half-life of about 30 years, is still present in the environment for about 300–600 years. Autoradiographic studies in mice have shown that 137-Cs is concentrated in greater quantity in the pancreas, particularly in exocrine cells, where most malignant PCs originate. Some methods of radiocesium removal and PC prevention are also suggested. But there is still a persistent, and not entirely disinterested, the controversy between damage from high and low exposure to ionizing radiations.

Side-chain alkylation of toluene with methanol over cesium ion-exchanged zeolites LSX and X catalysts

A Low-silica X (Si/Al=1.01, LSX) zeolite was successfully synthesized through a two-step hydrothermal method. Then, it was modified with Cs+ using the ion-exchange method and then the obtained sample was...