Bi3+ and Sb3+ doping (and codoping with lanthanides) in Cs2SnCl6 vacancy ordered perovskites and Cs2MInCl6 (M = Na, K, Ag) double perovskites has been shown to open up new opportunities for solid state lighting. Bi3+ and Sb3+ with ns2 outer electronic configuration can tailor both optical absorption and emission properties for phosphor-converted light emitting diode (pc-LEDs) applications. Therefore, the s-electron dopants (Bi3+ and Sb3+) act as both sensitizers and emitters. This is because the dopant s-electrons contribute near the band edges of the host, unlike the cases of d- and f-electron dopants. Consequently, Bi3+ doping can also act as a sensitizer for lanthanide luminescence in systems like Bi3+-Ln3+ codoped Cs2AgInCl6, where Ln = Er, Yb, Tb. In this perspective, we provide insights on the tailoring of electronic and optical properties by ns2 electron doping. These insights are then connected to the rational design of hosts, dopants, and codopants, for their potential applications. Finally, we discuss challenges and opportunities for future research.

Bi3+ and lanthanide ions have been codoped in metal oxides as optical sensitizers and emitters. But such codoping is not known in typical semiconductors such as Si, GaAs, and CdSe. Metal halide perovskite with coordination number 6 provides an opportunity to codope Bi3+ and lanthanide ions. Codoping of Bi3+ and Ln3+ (Ln=Er and Yb) in Cs2AgInCl6 double perovskite is presented. Bi3+‐Er3+ codoped Cs2AgInCl6 shows Er3+ f‐electron emission at 1540 nm (suitable for low‐loss optical communication). Bi3+ codoping decreases the excitation (absorption) energy, such that the samples can be excited with ca. 370 nm light. At that excitation, Bi3+‐Er3+ codoped Cs2AgInCl6 shows ca. 45 times higher emission intensity compared to the Er3+ doped Cs2AgInCl6. Similar results are also observed in Bi3+‐Yb3+ codoped sample emitting at 994 nm. A combination of temperature‐dependent (5.7 K to 423 K) photoluminescence and calculations is used to understand the optical sensitization and emission processes.

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Silver bismuth iodide (SBI) materials have recently gained attention as nontoxic alternatives to lead perovskites. Although most of the studies have been focusing on photovoltaic performance, the inherent ionic nature of SBI materials, their diffusive behavior, and influence on material/device stability is underexplored. Herein, AgBi2I7, Ag2BiI5, and Ag3BiI6 thin films are developed in controlled ambient humidity conditions with a decent efficiency up to 2.32%. While exploring the device stability, it is found that Ag3BiI6 exhibits a unique ion‐migration behavior where Ag+, Bi3+, and I− ions migrate and diffuse through the dopant‐free hole transport layer (HTL) leading to degradation. Interestingly, this ion‐migration behavior is relatively fast for the case of antisolvent‐processed Ag3BiI6 thin‐film‐based devices contrasting the case of without antisolvent and is not observed for other SBI material‐based devices. Theoretical calculations suggest that low decomposition enthalpy favors the decomposition of Ag3BiI6 to AgI and BiI3 causing migration of ions to the electrode which is protected by using a thick HTL . The new mechanism reported herein underlines the importance of SBI material composition and fundamental mechanism understanding on the stability of Ag3BiI6 material for better solar cell design and also in extending the applications of unique ion‐migration behavior in various optoelectronics.

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An epidemic of viral hepatitis, serologically characterized as due to non-A, non-B hepatitis, occurred in a village of South Delhi, India, in December, 1986, through January, 1987. Water contaminated with fecal matter was the apparent source of infection. Disease-associated virus-like particles were detected by immune electron microscopy in the feces of three patients within 5 days of illness. The virus-like particles were agglutinated by autologous acute-phase serum but not by convalescent serum. Rhesus monkeys inoculated with particle-containing fecal suspensions developed biochemical and morphologic features of acute, self-limited hepatitis. The findings in the present study and in earlier investigations of sporadic non-A, non-B hepatitis suggest that (i) the epidemic form and a proportion of sporadic cases of this infection in India may be related, both being enterically transmitted and associated with infection by a 27- to 32-nm virus-like particle, (ii) antibody responses to this virus occur early in disease and are transient and (iii) the rhesus monkey may prove to be a suitable model for studies of epidemic non-A, non-B hepatitis.

Garcinol, a polyisoprenylated benzophenone, is the medicinal component obtained from fruits and leaves of Garcinia indica (G. indica) and has traditionally been extensively used for its antioxidant and anti-inflammatory properties. In addition, it has been also been experimentally illustrated to elicit anti-cancer properties. Several in vitro and in vivo studies have illustrated the potential therapeutic efficiency of garcinol in management of different malignancies. It mainly acts as an inhibitor of cellular processes via regulation of transcription factors NF-κB and JAK/STAT3 in tumor cells and have been demonstrated to effectively inhibit growth of malignant cell population. Numerous studies have highlighted the anti-neoplastic potential of garcinol in different oncological transformations including colon cancer, breast cancer, prostate cancer, head and neck cancer, hepatocellular carcinoma, etc. However, use of garcinol is still in its pre-clinical stage and this is mainly attributed to the limitations of conclusive evaluation of pharmacological parameters. This necessitates evaluation of garcinol pharmacokinetics to precisely identify an appropriate dose and route of administration, tolerability, and potency under physiological conditions along with characterization of a therapeutic index. Hence, the research is presently ongoing in the dimension of exploring the precise metabolic mechanism of garcinol. Despite various lacunae, garcinol has presented with promising anti-cancer effects. Hence, this review is motivated by the constantly emerging and promising positive anti-cancerous effects of garcinol. This review is the first effort to summarize the mechanism of action of garcinol in modulation of anti-cancer effect via regulation of different cellular processes.