Flexible and Stretchable UV-B Light-Emitting Diodes

Nanostructured ultraviolet light sources operating in the UV-B spectral range (280-325 nm) are critical for dermatological therapy, horticulture, disinfection, and wearable optoelectronics. This work presents the first elastic UV-B light-emitting diode membranes based on GaN microwires with a core-shell AlGaN/GaN active region, addressing both optical efficiency and flexibility challenges. Microwires were grown on sapphire, encapsulated into polydimethylsiloxane, and integrated with two types of electrodes based on the patterned films of single-walled carbon nanotubes and silver nanowires. The proposed single walled carbon nanotubes -based elastic electrodes maintain initial resistivity at 10% biaxial stretching. The device emits in the UV-B range at 307-321 nm under bias, achieving a current density of ∼3.9 A/cm² at 18 V. The developed light-emitting diodes retain functionality under bending and 10% stretching, with a minimal spectral shift (<3 nm) and stable I-V characteristics, making it suitable for UV-B elastic applications.