Self-Assembly of Broadband White-Light Emitters

We
use organic cations to template the solution-state assembly
of corrugated lead halide layers in bulk crystalline materials. These
layered hybrids emit radiation across the entire visible spectrum
upon ultraviolet excitation. They are promising as single-source white-light
phosphors for use with ultraviolet light-emitting diodes in solid-state
lighting devices. The broadband emission provides high color rendition
and the chromaticity coordinates of the emission can be tuned through
halide substitution. We have isolated materials that emit the “warm”
white light sought for many indoor lighting applications as well as
“cold” white light that approximates the visible region
of the solar spectrum. Material syntheses are inexpensive and scalable
and binding agents are not required for film deposition, eliminating
problems of binder photodegradation. These well-defined and tunable
structures provide a flexible platform for studying the rare phenomenon
of intrinsic broadband emission from bulk materials.