van der Waals integration of GaN light-emitting diode arrays on foreign graphene films using semiconductor/graphene heterostructures

Abstract

We report the van der Waals integration of micropatterned GaN light-emitting diodes (LEDs) onto foreign graphene films. GaN micro-LEDs were selectively grown on a graphene substrate using a patterned SiO2 mask, and then the whole device structure was laterally fixed by a polyimide insulator to form a united layer. After device fabrication, the LED/graphene heterostructure device was piled on the foreign graphene layers using a typical wet transfer technique of 2D crystals where the bottom graphene layer of the heterostructure was adhered to the foreign graphene only by van der Waals interactions. The transferred micro-LEDs showed well-aligned crystallographic orientations as well as reliable device performances, including strong light emissions, good rectifying behaviors of the current density–voltage curve, and good simultaneity between the electroluminescence intensity and the applied currents, ensuring reliable electrical connections and mechanical adhesions of the light-emitting layer to the foreign graphene films. Furthermore, the reliable adhesiveness allowed us to achieve device wearability, while the LEDs exhibited homogeneous light emissions under various bending conditions because of negligible external stress in the discrete micro-LEDs.

Visible White‐Light Emission and Carrier Dynamics Observed in Full‐Series GaSe1‐xSx (0≤x≤1) Multilayers

“…1 and E 2g 1 (from x = 1 to x = 0) and E ″ (2) and E ″(4) (from x = 0 to x = 1) displayed in Figure 1a-c. In principle, the 𝜖 phase of D 3h 1 may contain a lot of sites symmetries of 6D 3h (1), 3C 3v (2), 2C 2 v (3), 3C s (6), and C 1 (12). [41] The 𝛽 phase of D 6h 4 could consist of many site symmetries including D 3d (2), 3D 3h (2), 2C 3v (4), C 2h (6), C 2v (6), C 2 (12), 2C s (12), and C 1 (24).…”

“…[4] In the pursuit of flexible, deformable, and large-area lightemitting diodes (LEDs), InGaN/GaN hexagonal micro-rod LEDs grown on 2D materials such as graphene on a sapphire substrate have been fabricated and studied. [5,6] However, the rigidity and hardness of the III-V nitride micro-rods and the sapphire substrate may hinder the softness and flexibility of the entire 2D light-emitting devices. Additionally, the hetero-epitaxy of nitrides on the graphene layer can also impede the uniformity of rod sizes in the In-GaN/GaN micro-rods.…”

Heteroepitaxially grown semiconductors on large-scale 2D nanomaterials for optoelectronics devices

“…e). [35] 그래핀을 지지하는 하부 기판에 텅스텐 등 금속성 소재를 사용하여 전기적 특성 및 방열 특성 등을 향상시킬 수도 있다. [36] 위치 및 형상을 제어할 수 있는 특성을 활용하는 또 다른 방식은 하부 그래핀을 전극 어레이 형태로 가공하 여 개별 소자를 제어 가능한 발광소자로 활용하는 방식 이다.…”

Role of Gold Nanoparticles in Gallium Nitride Growth for Potential Plasmonic Device Applications

“…10 Recently, GaN epitaxially grown was obtained by the van der Waals nucleation mechanism, archiving the obtention of high-quality films for optoelectronics. 24 However, the GaN films synthesized from these methods exhibit high spontaneous recombination rates that reduce the performance of current generator devices due to nonsuitability. 25 On the other hand, the use of metallic nanoparticles (i.e., gold, silver, and alloys) as nucleation centers in the production of GaN to overcome these challenges was already reported, 26−28 while Valenzuela-Hernandez et al 29 obtained wurtzite GaN samples with the hexagonal structure on Au/ Si(100).…”