III-Nitride full-scale high-resolution microdisplays

Abstract

We report the realization and properties of a high-resolution solid-state self-emissive microdisplay based on III-nitride semiconductor micro-size light emitting diodes (µLEDs) capable of delivering video graphics images. The luminance level of III-nitride microdisplays is several orders of magnitude higher than those of liquid crystal and organic-LED displays. The pixel emission intensity was almost constant over an operational temperature range from 100 to −100 °C. The outstanding performance is a direct attribute of III-nitride semiconductors. An energy efficient active drive scheme is accomplished by hybrid integration between µLED arrays and Si CMOS (complementary metal–oxide–semiconductor) active matrix integrated circuits. These integrated devices could play important roles in emerging fields such as biophotonics and optogenetics, as well as ultra-portable products such as next generation pico-projectors.

CMOS-Controlled Color-Tunable Smart Display

“…For such purposes, inorganic LEDs have attractions over conventional liquid crystal technology and organic LEDs (OLEDs), such as high efficiency and brightness, high reliability and stability, and the capability to operate under harsh temperature conditions [5], [6]. However, compared with liquid crystal technology and OLEDs [6]- [9], conventional thin-film inorganic LEDs fabricated from the same epilayer usually emit light at a single color determined by the specific quantum-well (QW) structure used. Such monochromatic emission limits the multicolor applications of these LEDs.…”

Emission aperture size limited the guided mode extraction characteristics of GaN-based ultrathin-film photonic crystal micro-light-emitting diodes

“…These experimental results of absolute output power are better than the literature shows. [3][4][5] The output power enhancement of varying PhC emission aperture size is caused by the limited the finite extraction length of PhC. Recently, double-embedded PhCs (DPhCs) for extraction of the guided mode in LEDs have been shown to have an extraction length of the fundamental mode of approximately 21-39 lm.…”

“…Therefore, the microdisplays based on monochromatic GaN l-LED arrays that are driven in the passive and active mode have been developed. [1][2][3] The GaN l-LEDs have a number of advantages, such as brightness and high efficiency, over conventional size LEDs, which have been obtained by several groups 4,5 and are suitable for numerous potential applications, such as biophotonics and visible light communications. 6 A pico-projector using the l-LED array as the optical engine must be provided with directional far-field distribution, to enhance the light output efficiency and avoid crosstalk.…”

Micro-pixel light emitting diodes: Impact of the chip process on microscopic electro- and photoluminescence

“…[1][2][3][4] The high efficiency, brightness, reliability, and stability, 5,6 even under harsh temperature conditions, make III-Nitride semiconductor LEDs ideal candidates for many applications in the consumer and automotive area. In combination with a converter and a pixel control unit, these lLED arrays can be used for adaptive front lighting systems (AFS).…”