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.

No abstract

Development of suitable materials that acts as an interface between the implant and tissues in body system structurally, mechanically and bio functionally is important for the success of tissue engineering. This motivated materials scientists and biologists to find out suitable bioactive materials for the aforementioned purpose. There has been growing interest in developing bioactive synthetic ceramics that could closely mimic natural apatite characteristics. Hydroxyapatite (HAp) has been widely used as a biocompatible ceramic but mainly for contact with bone tissue, due to its resemblance to mineral bone. This study presents the synthesis and characterization of HAp materials from different sources like bovine bone and fish scales and their application in tissue engineering. The phase purity and crystallinity of different calcined HAp powder was determined by XRD and FTIR analysis. The Thermo Gravimetric and Differential Thermal Analysis were carried out to show the thermal stability of the HAp powder. The morphology of the powder was observed under Scanning Electron Microscopy (SEM). Cytotoxicity evaluation of the developed powder was carried out in RAW macrophage like cell line media for an incubation period of 72 hours. These results proved the biocompatibility of HAp powders obtained from different biosources for tissue engineering applications.

Lead halide perovskites are seriously considered for next generation photovoltaic technology. They have a unique combination of easy synthesis, high efficiency, and cost-effective techniques. Still, the major concern is the toxicity of lead used in perovskite devices. The research community is still debating whether the amount of lead used in a solar cell really poses a danger or not. However, it is pretty clear that mitigating the lead leakage from the lead halide perovskite device is of utmost importance. In this review, we discuss new material chemistry approaches that can be applied to reduce the lead leakage/wastage from damaged lead halide perovskite solar cells. ECR (encapsulate, capture, and recycle) approaches have the potential to significantly reduce the environmental and health hazard risks of lead halide perovskite devices. Encapsulation by a self-healing material and rigid glass can help the perovskite survive the extreme conditions and avoid exposure of the perovskite layer to the external environment. Capturing of lead can also be done by an encapsulant layer that can very quickly and efficiently bind to lead, in the case that it leaks from the damaged perovskite device. Moreover, the recycling of damaged or decommissioned devices helps to avoid the lead wastage and contamination in the environment. Finally, we also discuss the potential of lead-free perovskite for optoelectronic applications.