http://dspace.nbuv.gov.ua:80/handle/123456789/114612 Thu, 09 Apr 2026 16:20:28 GMT 2026-04-09T16:20:28Z http://dspace.nbuv.gov.ua:80/bitstream/id/341303/ http://dspace.nbuv.gov.ua:80/handle/123456789/114612 http://dspace.nbuv.gov.ua:80/handle/123456789/121139 Study of supercapacitors with a double electrical layer based on activated carbon materials Budzulyak, I.M.; Kovalyuk, Z.D.; Motsnyi, F.V.; Orletskyi, V.B. It is proposed ecologically pure technology to obtain activated carbon. On the base of this carbon the supercapacitors were manufactured. Their characteristics were determined and compare with analogs obtained using ecologically dangerous materials. Tue, 01 Jan 2002 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/121139 2002-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/121138 Silicon carbide LED Vlaskina, S.I. Silicon carbide has been widely used as material for manufacturing yellow, red, green LED and optoelecronics devices (in¬dicators, screens). The silicon carbide LED technology has been in¬vestigated for improvement of their operational characteristics. This in¬cludes the influences of the surface processing (etching, annealing), the formation method for the p-n junctions and the contacts on the LED properties. Light-emitting devices used as light sources for optical-fiber communication lines. LED fabricated by Al⁺ ion-implanted in 6H-SiC and investigated their characteristics for an effective green LED. The brightness of the ion-implanted p-n junction was found to be two orders higher than that of diffusion p-n junction, and the best value was 2000-10000 cd/m² with passing current about 0.5 mA through area 50x50 mm and applied voltage about 2.6 ± 0.2 V. The ion-implanted structures showed a high stability of light in the temperature range of 77-600 K. Tue, 01 Jan 2002 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/121138 2002-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/121133 III-V material solar cells for space application Torchynska, T.V.; Polupan, G.P. The present paper is a review of current situation in space solar cell engineering. The comparison of the Si and III-V solar cell performances, as well as their parameter variation with temperature rise, radiation treatments and improving design were analyzed. The modern directions of the space solar cell development and international space projects, applied new types of solar cells, were discussed as well. Tue, 01 Jan 2002 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/121133 2002-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/121131 Dielectric, ferroelectric and piezoelectric properties of sputtered PZT thin films on Si substrates: influence of film thickness and orientation Haccart, T.; Cattan, E.; Remiens, D. Lead titanate zirconate Pb(Zr,Ti)O₃ (PZT) thin films were deposited on platinized silicon substrates by r.f. magnetron sputtering and crystallized with preferred (110) or (111) orientation by conventional annealing treatment. The film structure evolution was observed as a function of the film thickness. Whatever the film thickness in the range 0.07 - 3 mm, the preferred orientation of the film is maintained. The film microstructure and, in particular, grain sizes varied with the film thickness; more precisely, grain sizes increases, both for (111) and (110) films with the film thickness. The electrical properties such as dielectric, ferroelectric and piezoelectric ones were systematically evaluated functions of the film thickness and their orientation. The relative dielectric constant increases with the film thickness; a saturation value of 920 is attained for film thicknesses higher than 0.6 µm independently of the film orientation. The ferroelectric properties seems to be independent of the film orientation; the coercive field decrease with increasing the film thickness to attain a minimum value of 30 kV/cm for films thicker than 1 mm. The remanent polarization increases with the film thickness and reaches the maximum value of 20 mC/cm². An increase in the piezoelectric constant e₃₁ with increasing the film thickness was observed for two types of films. For films thicker than 0.6 mm, the e₃₁ coefficient remains constant: e₃₁eff.rem. = -4.5 C/m² (which corresponds to d₃₁eff.rem. = -38 pm/V). Identical behavior is observed for the d₃₃eff. coefficient but no saturation effect with the film thickness is observed. The ferroelectric domain walls motion and the interfacial effects could explain partly the observed behavior. Tue, 01 Jan 2002 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/121131 2002-01-01T00:00:00Z