Using ion beams for creation of nanostructures on the surface of high-stable materials

Main ion-beam etching techniques for creation of nanostructures on the surface of high-stable materials have been considered. Methods of information recording in the form of nanostructure on the metallic substrate surface have been analyzed. Application of glass substrate for creation long-term data carrier was proposed. Microrelief information record on the glass substrate surface was obtained using the ionbeam etching

Design of Nanostructured Luminofor Сoating for a Multi-Junction Solar Cell

Design of the highly efficient solar cells is a hot area of semiconductor physics and material science. One of the major concerns is a substantial shift between the solar radiation spectra and optical absorption spectra of a photoelectric transducer. A new method based on synthesis of luminophor layer functioning as a radiation converter was proposed. It’s shown that nanostructured pyrazoline coatings could convert the incoming solar radiation into the secondary optical radiation for optimal matching with the active spectral range of the solar cell. Results of the experimental investigation revealed high potential capabilities for optical properties engineering of the luminophor through laser annealing. It was found that produced samples of nanostructured organic composites are characterized by sufficiently enough spectral shift (200–400 nm) that can be varied by doping during synthesis, high quantum yield (near 80 %), and are enough stable under circumstances of intensive long term radiation.Зазначено, що розробка високоефективних сонячних елементів є актуальним напрямком як матеріалознавчої науки, так і фізики напівпровідників. Однією з найважливіших проблем, що потребують нагального вирішення, є значна невідповідність між спектром сонячного випромінювання і спектром поглинання фотоелемента. Запропоновано метод, що полягає в синтезі та нанесенні на поверхню фотоелемента люмінофорного шару, який функціонує як перетворювач електромагнітного випромінювання. Показано, що наноструктуроване піразолінове покриття здатне перетворювати падаюче сонячне випромінювання у вторинне оптичне випромінювання для оптимальної відповідності сонячного спектра та спектра поглинання фотоелемента. Результати експериментального дослідження показали широкі можливості у процесі створення такого типу покриття. Встановлено, що одержані наноструктуровані органічні композити характеризуються достатньою величиною спектрального зсуву (200 - 400 нм), що може варіюватися шляхом введення домішок у процесі синтезу люмінофору, високим квантовим виходом 80 % і є досить стабільними за умов довготривалого інтенсивного опромінення

Perspectives for using technology of laser thermolithography

Analyzed in this work are the requirements to an optical system for laser thermolithographic recording. It has been shown that possibilities of this type recording with decreasing the registered element sizes can be realized only when using special measures for stabilizing both exposing radiation power and duration of laser pulses. Using the thermolithographic method for making super-dense patterns also requires creation of a specific system for dynamic focusing with accuracy better than 100 nm. It has been shown that the specific heat of thermochemical reaction and thermal resistance of a substrate are critical parameters for this method

Is there any future of optical discs?

Considered in this paper are causes for cutting compact discs out of information technology market. It has been shown a search of new technological solutions for efficient use of CDs in archive data storage

High-density data recording via laser thermo-lithography and ion-beam etching

Pits 250 – 300 - nm wide were obtained on the surface of thin organic nanocomposite film using master-disc laser-burning station with 405 nm laser beam focused by 0.85 NA lens. The film with obtained pits was used as a mask for subsequent reactive ion-beam etching of glass substrate. Finally, 150 – 200-nm pits were performed on the substrate surface. Nanocomposite films were based on organic positive photoresist with a dye inclusions. This dye is characterized by wide absorption band within the spectral region 390–410 nm and can be evaporated by laser irradiation with the wavelength 405 n

Analysis of properties of optical carriers after long-term storage

Performed in this paper is the analysis of possibilities to create optical information carriers for long-term information storage. Adduced are the results of experimental investigations of properties inherent to optical carriers of the WORM type after 25-year storage. It has been shown that their micro-relief structure formed by using focused laser radiation on thin films of chalcogenide vitreous semiconductors had not been practically changed after storing them for the above mentioned period in non-heated areas

Formation of submicron relief structures on the surface of sapphire substrates

An analysis of technologies that allow creating microrelief structures on the surface of sapphire substrates has been carried out. It is shown that the most effective method of forming relief structures with submicron dimensions is ion beam   etching through a protective mask formed by photolithography. The main problems in creating a microrelief on the surface of sapphire substrates are the removal of static electric charge in the process of ion beam  etching of the substrates, as well as obtaining a protective mask with windows of specified sizes, through which etching of the sapphire substrate is performed

High-speed optical recording in vitreous chalcogenide thin films

Thin films of glassy chalcogenide semiconductor are widely used as recording media in optical data storage. To obtain relief micro- and nanoscale structures on the surface of optical master discs inorganic photoresists based on chalcogenide glassy semiconductors can be used. They have high resolution and allow for exposure by short laser pulses. Implementation of such exposure is promoted by increasing the speed of photostructural transformations at high powers of exposing radiation. This increase in the sensitivity is associated with both local heating by illumination and a high density of excited electron-hole pairs. The exposure mode of the inorganic photoresists based on glassy chalcogenide semiconductor pulses of 10⁻⁸-10⁻⁹ s is close to the threshold of local photothermal destruction. Significant impact on the value of the threshold of photothermal destruction effects the choice of the substrate material which determines the rate of heat removal from the irradiation area. Moreover, one also needs to consider the effect of pulsed annealing of the inorganic photoresist material on the process of selective etching. We have established an inversion of the selective etching of the inorganic negative photoresist based on As₂S₃ in the center of the irradiated zone. The diameter of this zone is about 20% of the diameter of exposing beam. After the selective etching in alkaline solution in the center of protrusions being formed on the substrate, there observed are some dimples with the depth of 30-50 nm. Prior to the processing of irradiated inorganic photoresist by the selective etching these dimples were absent and their appearance is not due to possible local material evaporation of the inorganic photoresist. A possible reason for the inversion of solubility of the inorganic photoresist could be pulsed annealing in the recording process

Recording of Micro/Nanosized Elements on Thin Films of Glassy Chalcogenide Semiconductors by Optical Radiation

Inorganic resists based on chalcogenide glassy semiconductor (CGS) films can be effectively used in the creation of micro- and nanoelements of optoelectronic devices, micro- and nanoelectromechanical systems, and diffractive optical elements. The use of these materials is based mainly on their sensitivity to different types of radiation, which causes phase and structural changes in CGS films, and transparency in the infrared range. A number of photoinduced changes are observed in CGS, which are associated with structural transformations, phase transitions, defect formation, and atomic diffusion. It is important to determine technologies for the formation of micro- and nanoscale structures on CGS films, which can be used in the creation of diffractive optical elements for optoelectronic devices. Increasing the resolution of recording media based on vitreous chalcogenide semiconductors can be achieved by choosing the recording modes and composition of glasses, in which the strongest nonlinearity of the exposure characteristics of photosensitive material, as well as the introduction into the structure of recording media nanoparticles of noble metals for excitation of plasmonic resonance

Method of aberration compensation in sapphire optical disks for the long term data storage

One of the actual problems today is creation of the long term data storage systems. This paper presents the research results that allow implementing technical solution proposed by the authors of this work a few years ago to create the long term storage optical discs based on single crystal sapphire. It is shown that the problem of data reading through the anisotropic substrate can be solved by using the single crystal optical compensating elements. The experimental results confirm an efficiency of the proposed method of aberration compensation for the long term data storage sapphire media