The contribution of STM techniques is unique in analyzing the topography and opto-electronic properties of the unknown materials.

Despite the high performance of bulk hybrid perovskites, the material/device stability is a critical issue originating from the perovskites’ degradation when exposed to an open-air atmosphere. 2D/quasi-2D perovskite materials have attracted much attention due to their high stability under ambient conditions compared to the bulk perovskite. Along with 2D perovskite, various charge transport materials, and additives were also employed in perovskite solar cells (PSCs). We carried out one such approach in this work, where Ti₃C₂T_x a typical representative of the 2-D family, called MXenes, has been employed as a passivation/interfacial layer between the quasi-2D perovskite and the hole transport layer. A PSC, passivated with MXenes, shows over 9% relative improvement in the performance and very high stability (∼99%) in an open-air atmosphere over 50 days as compared to its pristine device. The detailed investigation suggests the role of MXene as a passivator, an energy aligner, and a barrier to reduce the non-radiative recombination loss, provide pathways for effortless hole transportation, and protect from external environmental factors respectively. Moreover, transient absorption studies reveal that adding MXenes also affects the distribution and lifetime of quasi-2D phases in PSCs. As we delve into specific applications, such as the integration of MXenes as passivator/HTL interfacial layers in 2-D PSCs, we unlock the potential for enhanced device performance, showcasing MXenes as a driving force in the evolution of stable solar cell technologies.

Therapeutic resistance remains a critical barrier in oncology, frequently leading to cancer relapse after initial treatment response. Growing evidence suggests the presence of drug-tolerant persisters (DTPs), a rare subpopulation of cancer cells that survives chemotherapy by entering a reversible specific adaptation. Unlike classical cell resistance, the DTP phenotype is independent of genetic changes and maintained through dynamic regulatory mechanisms. DTPs are phenotypically heterogeneous and can exhibit stem-like and quiescent cell phenotypes, non- or slow proliferation, and remarkable plasticity due to a di-pause-like state and executing epithelial–mesenchymal transition (EMT) or transdifferentiation processes. Despite advances in research, the molecular mechanisms underlying DTPs’ biology and their role in cancer relapse remain only partially understood. The review summarizes the current progress in processes that lead to the acquisition of cellular persistence status, which, in turn, constitute areas of vulnerability that can be exploited in cancer therapy. We highlight anti-DTP therapeutic strategies, including epigenetic modification, cell signaling and transcriptional regulation, metabolic reprogramming, and modification of cell interactions within the tumor microenvironment. Furthermore, we focus on the potential role of nanomaterials in the combat against DTPs. Nanoparticles not only act as part of the drug delivery process, enabling precise DTP targeting and enhancing intracellular drug accumulation, but their intrinsic properties can also be used to eradicate DTPs directly or by enhancing the effectiveness of other therapeutic strategies. The integrated approach offers strong potential to eliminate tumor persistence, prevent recurrence, and improve long-term patient outcomes beyond conventional therapies.

The behavior of triple‐cation mixed halide perovskite solar cells (PSCs) under ultrashort laser pulse irradiation at varying fluences is investigated, with a focus on local heating effects observed in femtosecond transient absorption (TA) studies. The carrier cooling time constant is found to increase from 230 fs at 2 µJ cm⁻ ² to 1.3 ps at 2 mJ cm⁻ ² while the charge population decay accelerates from tens of nanoseconds to the picosecond range within the same fluence range. At fluences between 0.5 and 5 mJ cm ² , distinct oscillations in the TA signal (≈1.1 MHz) reveal the presence of coherent longitudinal acoustic phonons (CLAP). These phonons induce lattice strain propagating at the speed of sound through the perovskite layer and exhibit relatively long damping times. TA spectra further reveal a partially reversible segregation of iodide and bromide anions under pulsed excitation. Interestingly, higher local heating at increased pump fluences slows the segregation process, with time constants extending from 40 min at low fluences to 110 min at high fluences. However, the continuous irradiation results in significantly smaller segregation effects compared to ultrashort pulse irradiation.

The very high cost, scarcity and dissolubility of platinum (Pt) is the center of debates as a counter electrode (CE) in dye sensitized solar cells (DSSCs) research domain. To deal with such core issues, herein, novel low-cost and electro-catalytically active inter-metallic nickel aluminide (Ni₃Al) thin films have been fabricated successfully on fluorine-doped tin oxide substrates by DC magnetron sputtering at room temperature. For the first time, Ni₃Al has been utilized as a CE for DSSCs application. Further, the solar cell performance of Ni₃Al based DSSC has compared with the sputtered coated Pt thin film based DSSC performance. Under open atmospheric experimental preparation conditions (in air), a maximum power conversion efficiency of 3% has been achieved with Ni₃Al CE. The obtained efficiency is quite analogous to a DSSC fabricated with a Pt CE. Further, as-fabricated Ni₃Al CEs have exhibited better electrochemical catalytic activity and anti-corrosion effect than that of sputtered Pt CEs. The low-cost and excellent electrocatalytic properties of intermetallic Ni₃Al thin films may pave the way towards development of Pt-free CE for DSSCs.