Info
Info
News Article

Korean Team Makes 2D Light-emitting FETs

News

Multi-operation mode light-emitting field-effect transistor based on graphene and monolayer WSe2

2D transition metal dichalcogenides (TMDs) are promising materials for next-generation optoelectronic devices. They can emit strong light due to the large binding energies of excitons (quasiparticles composed of electron-hole pair) as well as an atomically thin nature.

In existing 2D light emitting devices, however, the simultaneous injection of electrons and holes into 2D materials has been challenging, which results in low light emission efficiency.

To overcome these problems, Gwan-Hyoung Lee's group in Seoul National University and Chul-Ho Lee's group in Korea University demonstrated all-2D light-emitting field-effect transistors (LEFETs) by staking 2D materials. They chose graphene and monolayer WSe2 as contact electrode and an ambipolar channel, respectively.

Typically, a junction between metal and semiconductor has a large energy barrier. It is the same at a junction of graphene and WSe2. However, Lee group used the barrier-tuneable graphene electrode as a key for the selective injection of electrons and holes. Since the work function of graphene can be tuned by an external electric field, the contact barrier height can be modulated in the graphene-contacted WSe2 transistor, enabling selective injection of electrons and holes at each graphene contact.

By controlling the densities of injected electrons and holes, the high efficiency of electroluminescence as high as 6 percent was achieved at room temperature.

In addition, the researchers showed that, by modulating the contacts and channel with separate three gates, the polarity and light emission of LEFETs can be controlled, showing great promises of the all-2D LEFETs in multi-digit logic devices and highly integrated optoelectronic circuitry.

'Multioperation mode light-emitting field-effect transistors based on van der Waals heterostructure' by Junyoung Koon et al; Advanced Materials, September 2020.



AngelTech Live III: Watch the virtual event ON-DEMAND!

AngelTech Live III was broadcast live on 12 April 2021, 10am BST, rebroadcast on 14 April (10am CTT) and 16 April (10am PST) and features online versions of the market-leading physical events: CS International and PIC International PLUS a brand new Silicon Semiconductor International Track!

The event covered the whole spectrum of key developments affecting the compound semiconductor industry. Over the last few months interest in deep-UV LEDs has rocketed, due to its capability to disinfect and sanitise areas and combat Covid-19. This was considered a roadmap for this device, along with technologies for boosting its output.

With 3 interactive sessions over 1 day AngelTech Live III proved to be a key event across the semiconductor and photonic integrated circuits calendar.

So make sure you sign up today and discover the latest cutting edge developments across the compound semiconductor and integrated photonics value chain.

REGISTER FREE

VIEW ON-DEMAND

Info
×
Search the news archive

To close this popup you can press escape or click the close icon.
×
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in:
 
X
Info
X
Info
{taasPodcastNotification}
Live Event