Bright electroluminescence in ambient conditions from WSe2 p-n diodes using pulsed injection
- Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences
- Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division
Transition metal dichalcogenide (TMDC) monolayers are promising materials for next-generation nanoscale optoelectronics, including high-speed light sources and detectors. However, most past reports on TMDC light-emitting diodes are limited to operation in high vacuum, while most applications require operation under ambient conditions. Here, we study the time-resolved electroluminescence of monolayer WSe2 p-n junctions under ambient conditions and identify the decay in current over time as the main issue preventing stable device operation. We show that pulsed voltage bias overcomes this issue and results in bright electroluminescence under ambient conditions. This is achieved in a simple single-gate structure, without the use of dual gates, heterostructures, or doping methods. Internal quantum efficiency of electroluminescence reaches ~1%, close to the photoluminescence quantum efficiency, indicating efficient exciton formation with injected carriers. Emission intensity is stable over hours of device operation. Finally, our device exhibits ~15 ns rise and fall times, the fastest direct modulation speed reported for TMDC light-emitting diodes.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; National Science Foundation (NSF); USDOD
- Grant/Contract Number:
- AC02-05CH11231; ECCS-0939514
- OSTI ID:
- 1638990
- Alternate ID(s):
- OSTI ID: 1530477
- Journal Information:
- Applied Physics Letters, Vol. 115, Issue 1; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Direct Observation of Gate-Tunable Dark Trions in Monolayer WSe 2
Observation of long-lived interlayer excitons in monolayer MoSe2–WSe2 heterostructures