Cardiomyopathies are often characterized by significant fibrotic remodelling of the heart, marked by an abnormal accumulation of collagen type I. Label free Raman spectroscopy, a non-invasive diagnostic technique, holds promise for monitoring biochemical changes throughout the initiation and progression of different diseases, including cardiomyopathies. This study demonstrates the effectiveness of 70% glycerol as a hyperosmotic immersion liquid for in-depth controlling the optical properties of ex vivo myocardium tissue during deep-UV Raman spectroscopy with 244 nm excitation. The results revealed a considerable enhancement in the intensities of Raman peak, particularly the amide I region after glycerol treatment. This occurred across all depths (0−120 µm) and glycerol treatment durations (30 and 60 min). A noticeable enhancement of the Raman peak at 1647 cm⁻¹ was also observed that is attributable to structural transformations of the collagen due to the dehydration induced by glycerol. This finding suggest that deep-UV Raman can be employed as a specific probe of the collagen environment. As the amide I region reflects structural changes in collagen type I, these findings propose the potential of deep-UV Raman spectroscopy in combination with glycerol as optical clearing agent for monitoring collagen modifications.

All-perovskite tandem solar cells are a promising photovoltaic technology, but their efficiency is strongly limited by the tunnel junction. The tunnel junction enables carrier tunneling and recombination, which depend on the interfacial band alignment. Through quantitative simulations using Silvaco Technology Computer Aided Design (TCAD), we find that hole tunneling is intrinsically more difficult than electron tunneling in the tunnel junction. Efficient tunnel junctions require minimizing the barrier for holes while maintaining a moderate barrier for electrons to balance tunneling. For the SnO₂/metal/PEDOT:PSS tunnel junction in all-perovskite tandem solar cells, tuning the metal work function achieves balanced electron and hole tunneling, reduces junction resistance, and directly enhances performance of tandem solar cells. This work provides quantitative design rules for tunnel junction optimization, offering a clear pathway toward high-performance all-perovskite tandem solar cells.