Physical parameters of the energy barrier of graphene/p CdTe Schottky diodes

Graphene/p CdTe Schottky diodes were obtained by spaying polyvinylpyrrolidone solutions of particles of multilayer graphene. It was established that the spray process does not affect the electrical parameters of the substrates when they are heated to a temperature of T-s = 523 K. The formation of graphene layers was confirmed by the study of Raman scattering spectra in the frequency range of 1000-3250 cm(-1), which correspond to the vibrations of carbon sp(2) bonds. The intense peak of the 2D band and its asymmetry indicate the presence of graphene on p CdTe substrates and its multilayer nature. Based on the study of the temperature dependence of the I V-characteristics, the diode properties of the investigated graphene/p CdTe structures were established, the energy barrier height q phi(k) = 0.75 eV and the temperature coefficient of its change d(q(p(k))IdT = 2.6.10(-3) eV/K were estimated. The temperature dependence of the series resistance of the structure was analyzed and the ionization energy of the energy level responsible for the equilibrium conductivity in the base material was determined. The analysis of the C V-characteristics measured in a wide frequency range from 10 kHz to 1000 kHz made it possible to determine the main physical parameters of the energy barrier, as well as the impurity concentration and its distribution in the p CdTe region. It was confirmed that the concentration of the electrically active acceptor impurity in the near -contact region of the p CdTe substrate coincides with the concentration of holes in the base material.