Solution-Grown ZnO Films toward Transparent and Smart Dual-Color Light-Emitting Diode

Abstract

An individual light-emitting diode (LED) capable of emitting different colors of light under different bias conditions not only allows for compact device integration but also extends the functionality of the LED beyond traditional illumination and display. Herein, we report a color-switchable LED based on solution-grown n-type ZnO on p-GaN/n-GaN heterojunction. The LED emits red light with a peak centered at ∼692 nm and a full width at half-maximum of ∼90 nm under forward bias, while it emits green light under reverse bias. These two lighting colors can be switched repeatedly by reversing the bias polarity. The bias-polarity-switched dual-color LED enables independent control over the lighting color and brightness of each emission with two-terminal operation. The results offer a promising strategy toward transparent, miniaturized, and smart LEDs, which hold great potential in optoelectronics and optical communication.

Nanocarbons with Different Dimensions as Noble-Metal-Free Co-Catalysts for Photocatalysts

“…It is no doubt that the composites exhibit enhanced photocatalytic activity. Different from TiO 2 , photocorrosion of ZnO during light irradiation hinders their practical application in the field of photocatalysis and its applications are limited to light-emitting diodes [32], gas sensors [33], and so forth. [34].…”

Realization of Nanostroke with a Violet-Light-Emitting Device with High Monochromaticity

“…For the challenge of fabricating reliable and reproducible p-type ZnO, researchers turn to a heterojunction with other p-type semiconductors, such as p-Si, − p-GaN, − or p-NiO. , LEDs based on ZnO nanowires and p–n junctions emit ultraviolet/violet light with a wide spectrum. However, their colors are tunable with doping, − coupling, bias conditions, interfacial layers, and so on. LEDs with a Schottky junction are also easy to fabricate, but their electroluminescence includes the range from ultraviolet , to infrared, , depending on different defects and densities …”

“…12,13 LEDs based on ZnO nanowires and p−n junctions emit ultraviolet/violet light with a wide spectrum. However, their colors are tunable with doping, 14−17 coupling, 18 bias conditions, 19 interfacial layers, 20 and so on. LEDs with a Schottky junction are also easy to fabricate, but their electroluminescence includes the range from ultraviolet 21,22 to infrared, 22,23 depending on different defects and densities.…”

Monolithic integration of AlGaInP-based red and InGaN-based green LEDs via adhesive bonding for multicolor emission

“…Therefore, alternative integration methods without the use of a transfer machine would be beneficial to realize high-resolution RGB full color displays in an industrial setting. One route could be achieved through interface designs such as ZnO/GaN or growth techniques of hetero junctions like n-p-n structures, although the lighting efficiency needs to be improved 22 , 23 . Another group suggested stacking wafer-level thin films of the III-V-based LEDs to realize multicolor pixels 24 .…”