Phys.org September 27, 2024 Excitons in monolayer semiconductors offer strong light–matter coupling, spin–valley locking and exceptional tunability allowing electrical switching of their optical response due to efficient interactions of excitonic emitters with free charge carriers forming trions and Fermi polarons. However, there are major limitations to how fast the light emission of these states can be tuned, restricting most applications to an essentially static regime. An international team of researchers (Italy, Sweden, Germany, Japan) demonstrated switching of excitonic light emitters in monolayer semiconductors on ultrafast picosecond time scales by applying short pulses in the terahertz spectral range following optical injection. […]
Tag Archives: Light emitters
Researchers discover new way to generate light through use of pre-existing defects in semiconductor materials
Nanowerk October 26, 2021 InGaN LEDs with considerably high indium concentrations remain difficult to manufacture using conventional semiconductor structures. An international team of researchers (Singapore, USA- MIT) leveraged the the formation of pyramids, the intrinsic defects in LED materials. V-pits, which result from naturally-existing dislocations in the material, directly forms indium-rich quantum dots that emit longer-wavelength light. By growing these structures on conventional silicon substrates, the need for patterning or unconventional substrates is further eliminated. The researchers demonstrated visual confirmation of their morphology. In addition to the formation of quantum dots, the nucleation of stacking faults – another intrinsic crystal […]
Nanostructure-based lasers for information and communication technologies
Phys.org August 18, 2021 Key applications in 5G and 6G optical networks require the utilization of laser sources to perform complex tasks at ultra-fast speed and to enable broadband, secure and energy efficient communications. An international team of researchers (France, USA – University of New Mexico) reviews recent findings and prospects on nanostructure based light emitters where active region is made with quantum-dot and quantum-dash nanostructures. To link the material and fundamental properties with the device physics, they closely examined spectral linewidth, polarization anisotropy, optical nonlinearities as well as microwave, dynamic and nonlinear properties. The paper focuses on photonic devices […]