The next generation of photodetectors must be able to deliver more than just intensity and spectral data. They need to be capable of detecting polarization. Adding polarization sensitivity to photodetectors requires materials and structures that can interact with light in new ways. Perovskite metasurfaces offer such a capability, combining strong light absorption with nanoscale patterning to unlock polarization-sensitive detection.

Metal halide perovskites are known for their efficient light emission, tunable optical properties, and compatibility with solution-based fabrication techniques such as spin-coating and inkjet printing. These qualities have made them suitable for developing compact microlasers with controllable emission wavelengths and high optical efficiency. However, maintaining stable laser performance under ambient conditions has remained a challenge.

A key factor behind this instability is phase inhomogeneity. When crystals form with a mixture of structural phases, the result is broadened emission and reduced optical stability. Phase-pure 2D tin halide flakes can overcome such an issue by providing uniform structures with consistent optical behavior, allowing perovskite lasers to operate more reliably under real-world conditions.

Light-emitting diodes (LEDs) have had quite an impact on modern technology, powering everything from smartphone displays to large-scale lighting. Yet, there is one thing LEDs cannot do easily and that's produce coherent light states. LED emission is broad and uncoordinated, as the light waves are not aligned in phase, so they spread in many directions and cannot form a sharp, focused beam. Lasers, in contrast, emit narrow and coherent beams but require a process called population inversion, which is energy demanding and harder to integrate into compact devices.

Researchers are turning to optically pumped perovskite LEDS as a promising way to produce coherent light without population inversion. Their operation depends on optically pumped polaritons, hybrid particles formed when light and matter strongly couple inside a microcavity. Optically pumped polaritons enable perovskite LEDs to combine the efficiency of traditional LEDs with the coherence of lasers, an effect that researchers examine using microspectrophotometry.

The ability to control light at the quantum level has long been constrained by the need for cryogenic temperatures and complex material systems. Because room temperatures cannot sustain quantum coherence, researchers have traditionally relied on cryogenic set ups and complex machines, despite their cost and size, to stabilize light-matter interactions. Room temperature polaritons offer an interesting alternative. Enabled through 2D perovskite systems, these polaritons form under ambient conditions, where the materials’ unique optical and structural properties naturally support strong coupling. As a result, room temperature 2D perovskite systems are paving the way to accessible, high-performance quantum photonic technologies