Nano-sized light emitting diodes by near field laser exposure

Abstract

We report a postfabrication process for the realization of nanosized light emitting diodes. The method is based on the exposure of the device to an Ar+ laser through an aperture near field optical microscope and can produce a large (>100 fold) increase in the electroluminescence within a near field hot spot as small as 440 nm. A study of morphological, photoluminescence and electroluminescence properties highlights the interplay between oxidation, annealing, and ablation processes for various laser exposure conditions.

Planar micro- and nano-patterning of GaN light-emitting diodes: Guidelines and limitations

“…9,16 To understand how this is possible, we consider a device with nano-point current injection. In this case, the LED mesa was 4 Â 4 lm 2 , the mesa height 2 lm, and the overall n-GaN thickness 3 lm.…”

“…6,9,14 Such techniques tend to allow simpler fabrication of very small features compared to approaches based on etching and in GaAs-based infrared LEDs, sub-micron pattern definition was demonstrated in this way. 15,16 Localized current aperturing in III-nitride LEDs can be achieved for example by patterning the p-metal contact or by local variation of the contact resistivity between the current spreading layer and the p-GaN. In either case, patterns with at least sub-10-lm resolution are possible because the pGaN layer is very thin and highly resistive, thus allowing only a small lateral spread of the injected hole-current before recombination in the junction region.…”

Post-fabrication control of evanescent tunnelling in photonic crystal molecules

“…21,25 We exposed the spatial region in the middle of a photonic molecule in order to perform a symmetric oxidation that should prevent the mode detuning. In addition, we choose a photonic molecule which show a very small value of X P1-P2 , where the disorder induced detuning is likely quite small.…”

A micrometer-size movable light emitting area in a resonant tunneling light emitting diode

“…The ability to spatially localize [1][2][3][4][5][6] and move 7-9 on a micrometer scale the emitting region in a light emitting diode (LED) is relevant for several applications including Lab-On-a-Chip experiments, bio-imaging, high-resolution micro-displays, optoelectronic integrated circuits, etc. A movable micrometer-size light emitting area has been achieved, recently, in organic LEDs (OLEDs) and transistors (OLETs).…”

“…[8][9][10] These drawbacks could be overcome in an inorganic LED, where the spatial control on a micrometer scale of the light emitting area is therefore highly desirable. So far, micrometer-and nanometer-size light emitting areas have been created in inorganic LEDs by different approaches, including lithographic [1][2][3][4] and laser-writing 5,6 techniques. However, these approaches do not provide a means of moving spatially the light emitting area created.…”