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.), the operating voltage (V-f) and the external quantum efficiency (eta(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 eta(ex) were 100 mW, 4.6 V and 5.9%, respectively.