Microstripe-array InGaN light-emitting diodes with individually addressable elements

Abstract

High-performance InGaN light-emitting diodes consisting of 120 side-by-side and individually addressable microstripe elements have been successfully fabricated. Each stripe in these devices is 24 pm in width and 3600 mu m long, with a center-to-center spacing between adjacent stripes of 34 mu m. The emission wavelengths demonstrated range from ultraviolet (UV) (370 nm) to blue (470 nm) and green (520 nm). The devices show good uniformity and performance due to finger-pattern n-electrodes running between adjacent stripes. In the case of the UV devices for example, turn-on voltages are around 3.5 V and continuous-wave output powers per stripe similar to 80 mu W at 20 mA. A major feature of these devices is their ability to generate pattern-programmable emission, which offers applications in areas including structured illumination wide-field sectioning optical microscopy

Fabrication of planar GaN-based micro-pixel light emitting diode arrays

“…1.a), this demonstrates that the CHF 3 pre-metallization plasma treatment prevents current leakage through the p-GaN-metal interface, equivalent to a very effective electrical passivation of the p-GaN surface. With a series resistance of ~80Ω, device A presents electrical characteristics as good as those previously reported for micro-stripe LEDs made with the standard mesa-etch process [5]. Optical measurements were also performed and results are plotted on Fig 2.b.…”

“…Optical measurements were also performed and results are plotted on Fig 2.b. An averaged output power of ~500µW at 20mA was obtained which is twice as high as the power already reported for a similar micro-stripe design made with the standard process [5]. We believe that the lower number of fabrication steps in the planar process may result in improved current spreading, and so to better efficiency.…”

“…For purposes of comparison, a micro-LED array layout corresponding to an earlier type of mesa-etched device was chosen and consists of 120 pixels, each 20 µm wide by 3.6 mm in length, with a gap between adjacent stripes of 14 µm [5]. This geometry allows also critical evaluation of issues such as cross-talk and current spreading.…”

Techniques for fully integrated intra-/inter-chip optical communication

“…The proposed optical interconnect architecture comprises a light source and an integrated driver, described in detail in [7], a detector similar to [5], and ultra-fast PPM coder/decoder logic. The PPM decoding process is achieved through a time-to-digital converter (TDC).…”

“…Optical data signals are generated, for example, in an integrated CPU by a micro LED similar to [7]. A sub-nanosecond optical pulse was recently demonstrated for this device using CMOS drivers that occupy a fraction of the area of a pad.…”