RESUMO
ZnO:Al/n-ZnSe/p-CdTe anisotype heterostructures with diode properties were fabricated by the high-frequency magnetron deposition of ZnO:Al and n-ZnSe thin films onto the surface of crystalline p-CdTe. The flow of currents limited by the space charge at forward voltages up to 0.45 V and tunneling currents at V > 0.45 V was established. A change in these current flow mechanisms was observed at reverse voltages V = -0.6 V. The main part of the energy barrier qÏk = 1 eV of the ZnO:Al/n-ZnSe/p-CdTe heterostructure was formed in the p-CdTe substrate, which was established from studies of capacitance-voltage (C-V) characteristics. A model of the energy diagram of the heterostructure is proposed.
RESUMO
We report on the analysis of optical, polarimetric, and electrical properties of propolis films and hybrid biomaterial-inorganic heterojunctions based on them. It was shown that the material of the propolis films belongs to wide-bandgap optically active substances with the light-scattering centers, which possess complex optical properties. The values of the specific resistance ρ(P)=1.9·107 Ω·cm and dielectric constant ε(P)=19.5 of the propolis film were determined from the spectral distribution of the real and imaginary components of its impedance at room temperature, respectively. The dominating current transport mechanisms through the hybrid bioinorganic heterojunction propolis/p-CdTe were established to be the interface-states-assisted generation-recombination within the depletion region via deep energy levels at forward bias as well as the leakage current through the shunt resistance at reverse bias.