Сhemiluminescent display

Investigation of organic liquid phase electroluminescence (traditionally, the so-called “electro-chemiluminescence” or “electrogenerated chemiluminescence”) is of special interest as a competitor for “liquid” and “solid” organic light emitted diodes (OLEDs). From the electrochemical point of view, chemiluminescence is a selfregenerating process providing high brightness light radiation due to recombination of oppositely charged dye radicals. Chemiluminescent displays have a competitive set of parameters: high light efficiency, low power consumption, low driving voltages, fast response time, high spatial resolution, very high optical transmission and wide operation temperature range. No polarizers or alignment layers are required. Samples of chemiluminescent displays, including matrix microdisplays and micromechanically made cells are available; its design and parameters are discussed in details. Theoretical and experimental investigations of thin film DC chemiluminescence phenomena are carried out. On the basis of obtained experimental results, the most important physical processes have been investigated: charge injection into solution and charge transfer by electrohydrodynamic flows. Further prospects of chemiluminescent display devices are discussed

Sponge-like nanostructured silicon for integrated emitters

A new approach to nanoporous silicon formation is proposed. Anomalies both in low current densities and low fluorine ion concentrations, which is lead to low uniformity of formed porous silicon, are under consideration. It is shown that at very low current densities and fluorine ion concentration high uniformity, high porosity nanoporous silicon layers can be created. Structural, electrical and optical properties of porous silicon formed in a wide range of current densities, doping levels of silicon substrates and fluorine concentrations are presented

Self-organized nanostructured anodic oxides for display applications

Electrochemical technologies have a high potential for display applications because of their cheapness and simplicity, easiness to scaling to large substrates and lowtemperature nature. However, in major display technologies the oxide films should be deposited on transparent conductive substrate, usually ITO on glass. For dielectric substrates like glasses, a special technology of current control is applied to anodizing metal films, which changes the oxide porous structure in a final stage and prevents formation of metal islands. To transform the residual metal nanowires into oxide, a special fading process similar to anoding bonding can be done. Usually, high reactivity electrolytes are used in the anodizing process, which destroys ITO layers. We have analyzed chemical properties of ITO in various anodizing electrolytes and found some suitable reagents and compositions. A lot of functional layers can be created by anodizing. For example, different filters may be formed by filling the pores by ink jet printing. Porous oxides can have low refractive indexes – lower than any bulk material, and can be used as effective antireflective coatings. A titanium oxide cover film forms “self-cleaning” surface due to its semiconductor photonics properties and oxygen production

Electrochemiluminescence: from submicron cells to matrix displays

Construction and basic principals of organic direct current electrolyteless electrochemiluminescent (ECL) displays are briefly described. On the basis of received experimental results the most impor­tant physical processes of ECL have been investigated: formation and structure of a double electrical layer at electrode - liquid dielectric interface, charge injection into solution and charge carrying by electrohydrodynamic flows. Practical applications, including matrix displays are discussed

Porous Silicon Avalanche LEDs and their Applications in Optoelectronics and Information Displays

The use of silicon based light emitting diodes may completely solve the problem of low compatibility of optoelectronics elements and silicon chip. At present time the most suitable kinds of Si-LEDs are monocrystal and porous silicon avalanche LEDs. They have advantages such as long operation lifetime (>10000 hours), continuous spectrum, which allows to filter RGB colors, operation voltages (<12 V), extremely sharp voltage-current characteristic, nanosecond response time, and high high operation current densities (up to 8000 A/cm$\text{}^{2}$ in pulse mode). Rather low energy efficiency (<1%) is not so significant for near to eyes (NTE) microdisplays. These advantages open a way to design a high performance and cost effective passive addressed microdisplays

Characterization of Porous Silicon Light Emitting Diodes in High Current Density Conditions

Experimental current-voltage and current-light intensity characteristics of Schottky diodes with the structure: metal (Al) - porous silicon - n-type silicon substrate are presented. The measurements are carried out with a pulsed current in the high current densities conditions, which usually lead to irreversible breakdown and damage the junctions if applied in continuous operation. Conditions and mechanism of Schottky diodes breakdown, based on avalanche multiplication of carriers, are analyzed and the limit of stimulating pulses duration, not yet leading to irreversible breakdown, is calculated. A microsecond current power pulses generator was designed and used to investigate the porous silicon light emitting diodes in the 2000...8000 A/cm(2) current density range. An explanation of the registered behaviour of the current-light intensity plots is presented

Anodizing technique for Liquid Crystal Displays

Specific self organized nanoscale structures, process of its formation by electrochemical treatment and its application for Liquid Crystal Displays (LCDs) are considered in this paper. Special pillar titania formation technology is proposed to overcome some restriction incidental to porous alumina alignment layers. Both materials allow designing extremely time-, ultraviolet (UV) - and temperature stable alignment layers. A new method based on anodizing in meniscus region at high current densities has been developed for adjustable tilt porous structures formation. Masking and changing of anodizing parameters can be used to control properties and shapes of the structures

Porous silicon light emitting diodes

Проанализировано развитие светоизлучающих диодов на основе наноструктурированного пористого кремния. Рассмотрены электрофизические свойства изучаемых светодиодов и физические явления, определяющие эти свойства. Обсуждены перспективы использования наноструктурированного пористого кремния в оптоэлектронных интегральных схемах

Physical properties in light emitting diodes on nanostructured silicon

Рассмотрены основные проблемы экспериментального исследования физических процессов в светоизлучающих диодах на пористом кремнии. Проведен краткий анализ соответствую­ щих физических процессов и методов их исследования. Предлагаемые экспериментальные и технологические решения направлены на улучшение воспроизводимости эксперимен­тальных результатов, создание основы для построения адекватных теоретических моделей, а также на практическую реализацию кремниевых светодиодов с улучшенной эффектив­ностью