Graphene as a Transparent Conductive Electrode in GaN-Based LEDs

Zhang, Hehe; Mischke, Jan; Mertin, W.; Bacher, G.

doi:10.3390/ma15062203

Cited by 15 publications

(17 citation statements)

References 111 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Work function ~ 4.0 eV ~7.5 eV ~ 4.47 eV cause an increase in its sheet resistance due to an increase in carrier scattering [18], [38], [81], [82]. emitting at 456 nm [27].…”

Section: Materials N-gan P-gan Pristine Graphenementioning

confidence: 99%

AlGaN nanowire deep ultraviolet light emitting diodes with graphene electrode

Parimoo

Zhang

Vafadar

et al. 2022

Applied Physics Letters

View full text Add to dashboard Cite

Despite graphene being an attractive transparent conductive electrode for semiconductor deep ultraviolet (UV) light emitting diodes (LEDs), there have been no experimental demonstrations of any kind of semiconductor deep UV LEDs using a graphene electrode. Moreover, although aluminum gallium nitride (AlGaN) alloys in the format of nanowires are an appealing platform for surface-emitting vertical semiconductor deep UV LEDs, in particular, at short wavelengths, there are few demonstrations of AlGaN nanowire UV LEDs with a graphene electrode. In this work, we show that transferred graphene can serve as the top electrode for AlGaN nanowire deep UV LEDs, and devices emitting down to around 240 nm are demonstrated. Compared to using metal, graphene improves both the light output power and external quantum efficiency. Nonetheless, devices with a graphene electrode show a more severe efficiency droop compared to devices with metal. Here, we attribute the heating effect associated with the large contact resistance to be the major reason for the severe efficiency droop in the devices with a graphene electrode. Detailed scanning electron microscopy and Raman scattering experiments suggest that the nanowire height nonuniformity is the main cause for the large contact resistance; this issue could be potentially alleviated by using nanowires grown by selective area epitaxy that is able to produce nanowires with uniform height. This work, therefore, not only demonstrates the shortest wavelength LEDs using a graphene electrode but also provides a viable path for surface-emitting vertical semiconductor deep UV LEDs at short wavelengths.

show abstract

“…Work function ~ 4.0 eV ~7.5 eV ~ 4.47 eV cause an increase in its sheet resistance due to an increase in carrier scattering [18], [38], [81], [82]. emitting at 456 nm [27].…”

Section: Materials N-gan P-gan Pristine Graphenementioning

confidence: 99%

AlGaN nanowire deep ultraviolet light emitting diodes with graphene electrode

Parimoo

Zhang

Vafadar

et al. 2022

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…This development will not only impact photovoltaics but also other devices such as LEDs, where strong progresses have been made in the use of 2D materials‐based TCE. [ 178 ] Moreover, the development of TCE at industrial level is now considered, and scalable production have been already demonstrated. [ 179 ]…”

Section: Perspectives On Future Materials For Space Pvmentioning

confidence: 99%

“…This development will not only impact photovoltaics but also other devices such as LEDs, where strong progresses have been made in the use of 2D materials-based TCE. [178] Moreover, the development of TCE at industrial level is now considered, and scalable production have been already demonstrated. [179] Concomitantly, 2D materials have been tested (on Earth) in space-relevant conditions as components of electronic devices such as transistors, sensors, etc.…”

Section: Perspectives On Future Materials For Space Pvmentioning

confidence: 99%

Solar Energy in Space Applications: Review and Technology Perspectives

Verduci

Romano

Brunetti

et al. 2022

Advanced Energy Materials

102

View full text Add to dashboard Cite

Solar cells (SCs) are the most ubiquitous and reliable energy generation systems for aerospace applications. Nowadays, III–V multijunction solar cells (MJSCs) represent the standard commercial technology for powering spacecraft, thanks to their high‐power conversion efficiency and certified reliability/stability while operating in orbit. Nevertheless, spacecraft companies are still using cheaper Si‐based SCs to amortize the launching costs of satellites. Moreover, in recent years, new SCs technologies based on Cu(In,Ga)Se2 (CIGS) and perovskite solar cells (PSCs) have emerged as promising candidates for aerospace power systems, because of their appealing properties such as lightweightness, flexibility, cost‐effective manufacturing, and exceptional radiation resistance. In this review the current advancements and future challenges of SCs for aerospace applications are critically discussed. In particular, for each type of SC, a description of the device's architecture, a summary of its performance, and a quantitative assessment of the radiation resistance are presented. Finally, considering the high potential that 2D‐materials (such as graphene, transition metal dichalcogenides, and transition metal carbides, nitrides, and carbonitrides) have in improving both performance and stability of SCs, a brief overview of some important results concerning the influence of radiation on both 2D materials‐based devices and monolayer of 2D materials is also included.

show abstract

“…Researchers have developed a number of strategies to displace incumbent ITO, including TCEs based on metal oxides 4 , 5 , carbon nanotubes 6 , 7 , graphene 8 , 9 , conductive polymers 10 , 11 , oxide/metal/oxide strutures 12 – 15 , and metal nanowire networks 15 – 19 . Metal nanowire networks are promising due to their high performance, high scalability, low cost, and flexibility 20 , 21 .…”

Section: Introductionmentioning

confidence: 99%

All-atmospheric fabrication of Ag–Cu core–shell nanowire transparent electrodes with Haacke figure of merit >600 × 10–3 Ω−1

DiGregorio

Miller

Prince

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Transparent conducting electrodes (TCEs) are essential components in devices such as touch screens, smart windows, and photovoltaics. Metal nanowire networks are promising next-generation TCEs, but best-performing examples rely on expensive metal catalysts (palladium or platinum), vacuum processing, or transfer processes that cannot be scaled. This work demonstrates a metal nanowire TCE fabrication process that focuses on high performance and simple fabrication. Here we combined direct and plating metallization processes on electrospun nanowires. We first directly metallize silver nanowires using reactive silver ink. The silver catalyzes subsequent copper plating to produce Ag–Cu core–shell nanowires and eliminates nanowire junction resistances. The process allows for tunable transmission and sheet resistance properties by adjusting electrospinning and plating time. We demonstrate state-of-the-art, low-haze TCEs using an all-atmospheric process with sheet resistances of 0.33 Ω sq−1 and visible light transmittances of 86% (including the substrate), leading to a Haacke figure of merit of 652 × 10–3 Ω−1. The core–shell nanowire electrode also demonstrates high chemical and bending durability.

show abstract

Graphene as a Transparent Conductive Electrode in GaN-Based LEDs

Cited by 15 publications

References 111 publications

AlGaN nanowire deep ultraviolet light emitting diodes with graphene electrode

AlGaN nanowire deep ultraviolet light emitting diodes with graphene electrode

Solar Energy in Space Applications: Review and Technology Perspectives

All-atmospheric fabrication of Ag–Cu core–shell nanowire transparent electrodes with Haacke figure of merit >600 × 10–3 Ω−1

Contact Info

Product

Resources

About