• • FeIn2Se4 photodetector exhibits broadband photoresponse from 405 to 638 nm excitation wavelengths, with strong absorption spanning 510–1028 nm, enabling versatile visible-to-NIR detection.
• • Angle-resolved polarized Raman spectroscopy reveals 60° periodic intensity variation in four characteristic Raman modes, confirming pronounced in-plane anisotropy for polarization-sensitive detection.
• • XPS analysis after two weeks of air exposure at 84.8% RH and 32°C shows only partial surface oxidation (In2O3 and SeO2 peaks), whereas binary chalcogenides like In2Se3 and FeSe degrade rapidly, demonstrating superior environmental stability.
• • Device maintained a pronounced temporal response after two weeks and a weak but measurable photoresponse after two months, indicating long-term operational durability under ambient conditions.