Terahertz Photoluminescence of Double Acceptors in Bulky Epitaxial HgCdTe Layers and HgTe/CdHgTe Structures with Quantum Wells

The effect of optical phonons on the quenching of photoluminescence of mercury vacancies in narrow-band solid solutions of CdHgTe with increasing temperature

“…The signal intensity of the long-wavelength (corresponding to photon energy from 3 to 11 meV) PL band of the MCT structure with cadmium fraction in the solid solution of 19% decreases with temperature increasing from 20 to 40 K by a factor of 3 [13]. This quenching of the PL signal can be associated with increase in the role of nonradiative transitions with the emission of acoustic phonons when holes are captured by the states of mercury vacancy.…”

“…Optical transitions from excited states to the ground level form the long-wavelength band of vacancy PL observed in [13]. Second columnionization energy of states.…”

“…For the first time, long-wavelength PL in the far infrared (IR) range associated with acceptor states in bulk MCT epitaxial layers and HgTe/CdHgTe heterostructures with quantum wells was observed in papers [12,13]. Lines were found in the PL spectra near quantum energies of 10 and 20 meV (the latter value is close to the ionization energy A −1 2 -center).…”

“…The PL studies in the paper [13] were carried out on a structure with electronic type of conduction, in which all acceptor centers were completely ionized. In this case, all mercury vacancies in the absence of illumination were in the A −2 2 charge state, and A −1 2 -centers, due to which the longest wavelength PL is observed, appeared because of the capture of holes excited by illumination from the valence band to mercury vacancies.…”

“…Note that in the paper [14] it was sufficient to take into account only spontaneous processes associated with acoustic phonons, the intensity of which weakly depends on temperature. To describe the mechanism of thermal quenching of the PL signal observed in [13], it is also necessary to take into account the stimulated emission of phonons, as well as the optical phonons effect on the dynamics of non-equilibrium carriers. The purpose of this paper is to calculate the intensity of nonradiative transitions of holes from the valence band to localized states of mercury vacancies with the emission of optical phonons and discuss the effect of these processes on intracenter photoluminescence.…”