Direct LED writing of submicron resist patterns: towards the fabrication of individually-addressable InGaN submicron stripe-shaped LED arrays

Submicron stripe-shaped InGaN light-emitting diode (LED) arrays with individually addressable capabilities are demonstrated. The critical submicronstripe metallic electrodes, which define the emission pattern, are formed by direct LED writing in a mask-free manner. The individually addressable submicron-stripe LEDs show excellent performance in terms of their electrical characteristics (with typical turn-on voltage of 3 V, operational stability and power output up to 28 μW at 3 mA). Unlike conventional broad-sized LEDs, the efficiency droop of the submicron-stripe LED is significantly suppressed-in fact, there is no efficiency droop for current densities up to 100 A/cm2. Furthermore, the submicron-stripe LED shows a lower temperature-dependent shift of the emission wavelength. The lateral emission width is increased with increasing injection current, resulting in a wider lateral emission size than the metallic submicron-stripe electrode. The underlying physics of these phenomena are analysed. Such submicron-stripe LED arrays open up promising applications in nanophotonics and bio-sensing.