Microscale Thermal Inhomogeneity Enabled Bandgap Engineering in Perovskite Nanowire Arrays

in the axial direction. The large thermal inhomogeneity is attributed to the ultra-low thermal conductivity of perovskites combined with reduced nanowire (NW) diameter. In addition, the gradient NWs exhibit excellent optoelectronic features suitable for further integration into functional devices. This work provides guidelines for the composition manipulation of perovskites through phononic engineering, extending their applications in ultracompact microspectrometers, spectral imaging sensors, and other miniaturized optoelectronic devices.