K. Bartkiewicz

Optical properties of metallophthalocyanine compounds thin films

This work contains investigation results of the linear and nonlinear optical properties of metallophthalocyanines (Cu, Co, Zn, and Mg) and metallophthalocyanine chlorides (Al, Ga) thin films which were grown by physical vapor deposition (PVD) technique in high vacuum on transparent (quartz) and semiconductor (silica) substrates. Spectral properties of these films were examined using transmission, SGH and THG technique. Structural properties were investigated by AFM measurements. Transmission spectra were shown a large influence of intermolecular interaction on spectral properties of metallophthalocyanines and metallophthalocyanine chlorides. The influence of films thickness and annealing process of samples on their optical properties were also determined. The thickness dependence was connected with morphology of the film while annealing was caused change in polymorph phase. The measurements of transmission, SHG and THG spectra were allowed to determine optical constant of these films.

Photoluminescence of electrochemically etched porous silicon coated with small-molecule based thin organic films

In this paper, photoluminescence (PL) spectra of porous silicon (PSi) prepared by electrochemical anodisation coated with small-molecule based thin organic films are presented. Thin layers of copper phthalocyanine (CuPc) and tris(8-hydroxyquinoline) aluminium (Alq3) were deposited on PSi using the conventional thermal evaporation in high vacuum. Presented structures exhibit strong photoluminescence in visible region at room temperature under pulsed UV excitation. PL spectra of Alq3 deposited on glass and PSi layer without organic film are presented for intercomparison. The shapes of PL spectra of PSi/organic structures depends on material used and exhibit multiband structure. Properties of PSi/organic luminescence can be explained by penetration of organic material into PSi skeleton and interaction between carriers in PSi and deposited material.

Pulsed laser deposition of hafnium oxide on quartz substrate

In this paper, we report the experimental investigation of optical properties of HfO2 (hafnium oxide) thin films grown on quartz substrates by pulsed laser deposition (PLD) method [1]. Cold pressed powders of hafnium oxide (HfO2 98% - Aldrich Chem. Co.) were used as the target for deposition process. The transparent quartz substrate was heated up to temperature in the range between 200 and 600 °C. Optical properties of the films were investigated by transmittance in the ultra-violet, visible and near infrared range and photoluminescence spectroscopy. We measure the photo-luminescence spectra and dynamics of luminescence process [2]. The PL spectra contained one strong maximum at 385 nm and the peak intensity decreases rapidly with increasing temperature. Optical properties are closely related to the structure of the hafnium oxide thin films.

Study of photoadmittance and admittance of porous silicon layers

In this work, we investigated electrical properties of Al/PS/p-Si structures. Admittance spectroscopy is one of the major semiconductor diagnostic techniques. Frequency, voltage and wavelengths dependencies of admittance will be analyzed in detail. It will be useful for better understanding of fundamental electrical properties of porous silicon.

Photoluminescence of MgO thin films on Si (111) substrate, prepared by sol-gel method

Here we present the results of the measurements of photoluminescence properties of thin films of MgO (magnesium oxide) on Si substrate (mono-crystalline (111) silicon). The samples were prepared by the sol-gel method that is very simple method for fabrication metal oxide layers on different kind of substrates. We carried out the photoluminescence experiments at a wide range of temperatures from 10 to 300 K. We summarize how shape complexity of registered spectra depends on the temperature and the preparation conditions.

Investigations of temperature dependent photoluminescence process in MgO thin films

Pulsed laser deposition (PLD) technique (called also laser ablation) has been employed to grow magnesium oxide thin films on quartz wafers. The optical properties of MgO thin films were studied using temperature dependent photoluminescence measurements. The structural properties of the MgO thin films were carried out using X-ray method. A strong dependence of the films structure, the crystalline quality and the optical properties of investigated films caused by variation of substrates temperature was observed.

Photoluminescence of ZnO thin films on Si substrate

In this paper photoluminescence (PL) properties of ZnO (zinc oxide) thin films on Si substrates are presented. Samples were prepared by sol-gel method. Photoluminescence experiments where carried out at different temperatures (10 K- 300 K). Registered spectra exhibit multiband structure witch depends on the temperature and preparation conditions.

Structural and optical properties of as-grown and annealed Alq 3 thin films

This work contains investigation results of the structural and optical properties of aluminum (III) tris(8-hydroxyquinoline) - Alq3 thin films. The films were successfully grown by physical vapor deposition (PVD) technique in high vacuum on transparent (quartz) and semiconductor (n-type silica) substrates kept at room temperature during the deposition process. Selected films were annealed after fabrication in ambient atmosphere for 24 hours at the temperature equal to 50°C, 100°C and 150°C. Spectral properties of these films were examined using transmission, photoluminescence, SGH and THG technique. The experimental spectra were allowed to determine optical constant of the films. Structural properties were investigated by AFM measurements. The Alq3 films exhibit high structural quality regardless of the annealing process, but the stability of the film can be improved by using an appropriate temperature during the annealing process. We find that the optical properties were strictly connected with the morphology and the annealing process can significantly change the structural properties of the films.

Photoluminescence spectra of porous silicon modified by copper phthalocyanine coating

In this paper we present photoluminescence (PL) spectra of porous silicon (PSi) coated with thin top layer of copper phthalocyanine (CuPc). PSi was by electrochemical anodisation method prepared. CuPc based thin organic film was using physical vapor deposition (PVD) in high vacuum on the top of fresh PSi deposited. PL was under pulsed excitation measured and samples were in vacuum enclosed. PSi/CuPc samples exhibit strong photoluminescence in visible region at room temperature. Observed PL spectra exhibit multiband structure and such structure changes in red region compared to “clean” PSi. Properties of PSi/organic luminescence can be explained by penetration of organic material into PSi skeleton and interaction between carriers in PSi and deposited material.

Optical properties of MgO thin films on quartz substrate prepared by sol-gel method

In this paper the results of measurements of the optical properties of MgO thin films prepared by a sol-gel method on quartz substrates are presented. Measurements of the transmission (at the room temperature) and photoluminescence (in the range from 10 K to 325 K) were carried out. Three samples annealed at the different temperatures: 773 K, 1023 K and 1273 K have been examined.