The electrical properties of nonirradiated and electron irradiated structures, containing a polycrystalline thin layer of CdS, sandwiched between two gold electrodes, were investigated. The thin films of CdS, obtained through thermal-vacuum evaporation on the glass substrate at a temperature of 220 °C, were subjected to two sessions of irradiation with 7 MeV electrons to the fluences of 4×1015 and 6×1015 e/cm2, respectively. In the case of nonirradiated structures, under low voltages, the Ohm’s law is followed with a thermally activated electron concentration of n0≅3×1016 cm−3, an electron mobility μ0≅0.1 cm2/V s and a room temperature electrical conductivity σ0≅4×10−4 Ω−1 cm−1. In this range of voltage the electron irradiation induces a small increase in the activation energy of mobility, determining, of course, a small decreasing of the mobility. At high-applied voltage, there is a space-charge-limited conductivity controlled by a single trap level having the depth of Ec−Et≅0.086 eV and the total trap concentration Nt≅8.9×1015 cm−3. In this range of voltage, the electron irradiation modifies the trap distribution. After the first session of irradiation a uniform trap distribution appears and after the second session, an exponential trap distribution was induced in the band gap of CdS layer. All the induced trap distributions are characterized and their effect on the charge transport mechanisms is discussed.

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Electrical properties of nonirradiated and electron-irradiated thin layers of CdSe, sandwiched between two gold electrodes, were investigated. Thin films of CdSe, prepared by thermal-vacuum evaporation on glass substrate at a temperature of 220 °C, were subjected to two sessions of irradiation with 7 MeV electrons to the fluences of 2×1015 and 4×1015 e/cm2, respectively. The current–voltage characteristics, recorded at temperatures in the range 150–350 K, showed that the Ohm’s law is followed at low-applied voltages, in both nonirradiated and irradiated CdSe layers. In the range of high-applied voltages, the space-charge-limited current (SCLC), controlled by a Gaussian trap distribution, placed in the vicinity of the Fermi level, has been identified as the dominant conduction mechanism. An analysis in the frame of SCLC theory allowed us to obtain the parameters characterizing the trap distribution and their changes induced by electron irradiation.

The p–n heterojunction ITO/Chl a/TPyP/Al [Chl a – chlorophyll a and TPyP – 5, 10, 15, 20‐tetra(4‐pyrydil)21H, 23H‐porphine] photovoltaic cells are prepared by electrodeposition of Chl a onto a conductive indium–tin oxide electrode (ITO), followed by successive vacuum deposition of TPyP layer and Al top electrode. The studied dark (J–U) and photovoltaic characteristics, especially the action spectra, suggest the presence of a barrier at the Chl a/TPyP interface. The typical parameters of a photovoltaic cell, under an incident light power of 20 μW/cm2 at 470 nm, are reported. As compared with Chl a/Al Schottky cells, the performance of the fabricated two‐layer cells shows an important improvement.

Three-layered organic solar cells with an interlayer of codeposited dyes of ptype Copper Phthalocyanine (CuPc) and n-type 5,10,15,20-Tetra (4-Pyridil)21H,23H-Porphine (TPyP) between the respective dye layers were prepared and characterised. The analysis of their dark la lumibre avec une longueur d'onde de 520 nm et une intensit4 lumineuse de 30 ~IW cm~1.