High Output Power 365 nm Ultraviolet Light Emitting Diode of GaN-Free Structure

We have fabricated high-power ultraviolet (UV) light emitting diodes (LEDs). Epi-layers of UV LEDs were grown on high-quality GaN templates with sapphire substrates, and then the GaN templates and the sapphire substrates were removed by using laser-induced liftoff and polishing techniques in order to reduce the absorption of UV light by the GaN layer. As a result, we obtained the GaN-free UV LEDs. When this UV LED was operated at a forward-bias pulsed current of 500 mA at room temperature (RT), the peak wavelength, the output power ( P o ), the operating voltage ( V f ) and the external quantum efficiency (η ex ) were 365 nm, 118 mW, 4.9 V and 6.9%, respectively. On the other hand, at a forward-bias direct current of 500 mA at RT, P o , V f and η ex were 100 mW, 4.6 V and 5.9%, respectively.