Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 1639002

Centimeter-Scale and Visible Wavelength Monolayer Light-Emitting Devices

Cho, Joy·Amani, Matin·Lien, Der‐Hsien·Kim, Hyungjin·Yeh, Matthew·Wang, Vivian·Tan, Chaoliang·Javey, Ali
View original source ↗Read source document ↗Export metadata ↓

Abstract

Monolayer 2D transition metal dichalcogenides (TMDCs) have shown great promise for optoelectronic applications due to their direct bandgaps and unique physical properties. In particular, they can possess photoluminescence quantum yields (PL QY) approaching unity at the ultimate thickness limit, making their application in light-emitting devices highly promising. In this research, large-area WS 2 grown via chemical vapor deposition is synthesized and characterized for visible (red) light-emitting devices. Detail optical characterization of the synthesized films is performed, which show peak PL QY as high as 12%. Electrically pumped emission from the synthetic WS 2 is achieved utilizing a transient-mode electroluminescence device structure, which consists of a single metal–semiconductor contact and alternating gate fields to achieve bipolar emission. Utilizing this aforementioned structure, a centimeter-scale ( ≈ 0.5 cm 2 ) visible (640 nm) display is demonstrated, fabricated using TMDCs to showcase the potential of this material system for display applications.

Explore related subjects

36 MATERIALS SCIENCEWS2chemical vapor depositionelectroluminescencemonolayer displaytransition metal dichalcogenidevisible emission

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Cho, Joy, Amani, Matin, Lien, Der‐Hsien, Kim, Hyungjin, Yeh, Matthew, Wang, Vivian, Tan, Chaoliang, Javey, Ali. 2019-12-02. Centimeter-Scale and Visible Wavelength Monolayer Light-Emitting Devices. https://doi.org/10.1002/adfm.201907941

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2026

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗