The moisture‐induced structural decomposition of lead halide perovskites is the major challenge in solar cells and light‐emitting diodes based on perovskites as the active material. The presence of moisture results in the structural conversion of cubic 3D CsPbBr3 nanocrystals to 2D CsPb2Br5 nanosheets before its decomposition to PbBr2. The capping agent used, oleyl amine, plays a crucial role in this structural transformation. The presence of moisture converts the capping agent, oleyl amine, to its salt, which transforms the 3D CsPbBr3 perovskite nanocrystals to 2D CsPb2Br5 nanosheets. Further, these CsPb2Br5 nanosheets decompose to trigonal PbBr2, in the presence of higher amounts of water. Also, the amount of capping agent, oleyl amine, plays an important role in the rate of moisture‐induced structural transformations. The rate of decomposition increases with the amount of oleyl amine used as a result of the reaction of water with the excess ligands. By revealing the exact mechanism of the structural alterations in the presence of water, new design strategies can be used to prevent the decomposition of perovskites.

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Survey studies conducted in the rice growing districts of Telangana, revealed that incidence of stem rot disease varied from field to field (0 to 15%) in the surveyed districts of Khammam and Warangal. The disease incidence was varied from location to location. Highest disease incidence was recorded in late transplanted as compared to early transplanted crop. Maximum stem rot incidence (14.8%) was recorded in rice-rice followed by rice-groundnut (3.8%), rice-maize (2.8%) and sunhemprice-maize-vegetables (2.1%). Similarly, highest disease incidence was found in clay loam soils (14.0%), followed by clay soils (8.7%), loamy soils (7.8%), while lowest incidence of stem rot was noted in fields with sandy soils (2.7%) and sandy loam soils (2.6%). The fields received with 151-180 kg N ha -1 showed highest disease incidence (11.1%) followed by 120-150 kg N ha -1 (8.1%) and 100-120 kg N ha -1 (2.5%). Maximum disease incidence of stem rot was recorded in the fields which received pretilachlor (7.9%) as compared to the fields received butachlor (2.5%).studies conducted in the rice growing districts of Andhra Pradesh, revealed that incidence of stem. The mycoflora and bacteria were isolated from rhizosphere soil associated with diseased rice plants during the survey on Martin medium and soil extract agar medium, respectively. Mycoflora viz., Aspergillus flavus, A. niger, Cladosporium, Trichoderma viride isolate-1 and 2 while bacterial isolates viz., Pseudomonas fluorescens (BI-1), isolate-2 (BI-2), isolate-3 (BI-3), isolate-4 (BI-4), isolate-5 (BI-5) were found to be antagonistic to test pathogen S. oryzae. The detected mycoflora and bacterial isolates were further screened following dual culture technique and the results indicated that among mycoflora screened, T. viride (T1) was found to have most potential antagonistic effect with maximum inhibition (75.3 %) of test pathogen. Similarly among antagonistic bacterial isolates screened P. fluorescens (BI-1) was found to be highly effective in inhibiting the test pathogen by 77.2 per cent. These potential biocontrol agents can be exploited as an integrated approach in the management of stem rot of rice. The compatibility studies between T. viride (T 1 ) and P. fluorescens (BI-1) following dual culture technique under in vitro conditions indicated that the per cent inhibition of T. viride (T 1 ) by P. fluorescens was 5.0 per cent, while no inhibition was observed in the growth of P. fluorescens. Out of six fungicides tested, Hexaconazole @ 200 ppm and Propiconazole @m100 ppm completely inhibited S. oryzae in poisoned medium. Out of two herbicides tested, the inhibition of test pathogen was high (97.1%) in Butachlor (400 ppm) and least (28.0%) in Oxadiargyl (150 ppm). In compatibility studies, T. viride (T 1 ) was incompatible with fungicides Propiconazole (100 ppm) and Hexaconazole (200 ppm). However, it was 60.6 per cent inhibited Studies on disease incidence and efficacy of fungicides, herbicides and antagonists micro flora against stem rot of rice (Sclerotium oryzae) along w...

Photocatalytic solvent-assisted anion exchange of lead halide perovskites are extremely important, as it can tune the redox properties/band positions of the perovskite nanocrystals. Among that, the generation of chloride ions from the solvents chloroform and dichloromethane by accepting an electron from the photoexcited CsPbBr 3 nanocrystals and the resulting anion exchanges are investigated. The redox potentials of the solvent molecules and the band positions of the semiconductor allow for the photoinduced electron transfer process, thermodynamically, in these two solvents. However, the presence of a better electron acceptor N-bromosuccinimide (NBS) can prevent the photocatalytic solvent-assisted chloride ion exchange reactions in CsPbBr 3 . The preferential interaction of Pb 2+ of lead halide perovskites with the bromide ions in preference to Cl − , as a result of Pearson's hard soft acid base theory, stabilizes CsPbBr 3 nanocrystals. This is confirmed by using bromine-containing chloroform as the solvent. Interestingly, in the presence of NBS/ bromine, the anion exchange with chloride ions formed by the reduction of solvents can be prevented. The present investigations can give insights into the mechanistic aspects of the anion exchange reaction and suggest new methodologies to stabilize CsPbBr 3 nanocrystals in chlorine-containing solvents.

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