  We develop the device model for the proposed injection (electrically) driven
thermal light emitters (IDLEs) based on the vertical Hexagonal Boron Nitride
Layer/Graphene Layer/ Hexagonal Boron Nitride Layer (hBNL/GL/hBNL)
heterostructures and analyze their dynamic response. The operation of the IDLEs
is associated with the light emission of the hot two-dimensional electron-hole
plasma (2DEHP) generated in the GL by both the lateral injection from the side
contacts and the vertical injection through the hBNL (combined injection)
heating the 2DEHP. The temporal variation of the injection current results in
the variation of the carrier effective temperature and their density in the GL
leading to the modulation of the output light. We determine the mechanisms
limiting the IDLE efficiency and the maximum light modulation frequency. A
large difference between the carrier and lattice temperatures the IDLEs with an
effective heat removal enables a fairly large modulation depth at the
modulation frequencies about dozen of GHz in contrast to the standard
incandescent lamps. We compare the IDLEs with the combined injection under
consideration and IDLEs using the carrier Joule heating by lateral current.
  The obtained results can be used for the IDLE optimization.
