IR-range photoinduced diode effect in the manganese-substituted bismuth ferrite films

Abstract

The photoinduced diode effect has been found in BiMn X Fe 1−X O 3 (0<Х<0.15) films in the near-infrared and violet spectral ranges in a wide temperature interval. The dependences of the diode effect on temperature, wavelength, and illumination power have been established. The mechanism of the ferroelectric diode has been determined using its I-V characteristics at different illumination powers, optical spectra, far-infrared absorption spectra, and electric polarization hysteresis. The interplay between the photodiode effect and conductivity mechanism has been elucidated. The model of strong Coulomb potential fluctuations and quantum well asymmetry caused by the electric polarization in the film and difference between the times of carrier thermalization and recombination of electrons and holes is proposed.

Electric Power Sources Based on the Seebeck Effect of Manganese Sulfides with Rare Earth Substitution

“…3c for X = 0.3, dependence of temperature the thermal EMF has the form typical for semiconductors with a non-activation type of conductivity α = A + BT. Parameters B and A differ by an order of magnitude in the region of low 80K<T<350K with B = 2.8•10 -5 , A = 0.004 mV/K and high 350K<T<600K temperatures with B = 1.9•10 -4 , A = 0.05 mV/K [28].…”

“…The mechanism of Seebeck coefficient (thermal EMF) generation in semiconductors in the paramagnetic region is caused by electron entrainment by phonons. The interaction of holes with long-wave acoustic phonons leads to a power dependence α(T)~T −3.5 [22], which manifests itself in semiconductors at low temperatures of 50 -100 K. The second mechanism is associated with current carriers: electrons or holes [28][29][30][31]. The value of thermopower in metals is determined by the density of states at the Fermi level and the Fermi energy.…”

Electrical Properties of the Polycrystalline BiFe0.95Co0.05O3 Films

“…In the previously investigated manganese-substituted bismuth ferrite BiMn X Fe 1 -X O 3 (0 < X < 0.15) films, a photoinduced diode effect was found in the near-infrared and violet spectral regions in a wide temperature range [20]. The temperature, wavelength, and illumination power dependences of the diode effect have been established.…”

“…It was found that the E g value determined by extrapolating the straight portion of the dependence of (αhν) 2 on the photon energy up to intersection with the abscissa axis is about 2.8 eV. The cationic substitution of cobalt, in contrast to the substitution of manganese, leads to an increase in the gap energy, which is E g = 2.4 eV for BiFe 0.95 Mn 0.05 O 3 [20].…”