Light emission characteristics and mechanics of foldable inorganic light-emitting diodes.

Organic light emitting diodes (OLEDs) offer attractive alternatives to conventional inorganic devices due to their ability to be deposited over large areas on amorphous, thin fl exible substrates, for systems with lightweight, durable, and compact designs. [ 1 , 2 ] Recent work suggests that inorganic light-emitting diode (ILED) technologies can be adapted to reproduce many of these characteristics, [ 3 ] while at the same time providing performance advantages in brightness, robust operation and effi ciency. [ 3–5 ] Here we report advances in this type of ILED approach designed to enable degrees of bendability than signifi cantly exceed those previously achieved, [ 3 ] by exploiting concepts of neutral mechanical plane designs that we successfully developed for use in other fl exible inorganic device technologies in electronics [ 6 ] and photovoltaics. [ 7 ] The studies include quantitative analysis of the underlying mechanics, with the fi rst direct connections between such calculations and device performance through experimental measurements of bending induced shifts in the emission wavelength. The results provide strategies to achieve bending to radii as small as 0.7 mm with