Multilayer diode

Fig. 12. Schematic of surface-emitting laser diodes where U represents the active region (a) planar cavity surface-emitting laser diode (PCSEL) with 45° etched reflectors and (b) vertical cavity surface-emitting laser diode (VCSEL) with semiconductor-based multilayer mirror stacks grown into the stmcture.

Multilayered structures play an important role in the production of, e.g., biomaterials, catalysts, corrosion protectors, detectors/diodes, gas and humidity sensors, integral circuits, optical parts, solar cells, and wear protection materials. One of the most sophisticated developments is a head-up-display (HUD) for cars, consisting of a polycarbonate substrate and a series of the layers Cr (25 nm), A1 (150 nm), SiO, (55 nm), TiO, (31 nm), and SiO, (8 nm). Such systems should be characterized by non-destructive analytical methods. 

Adjustable Workbench (PAW) instrument assembly. The SH shown in Figs. 3.15 and 3.16 contains the electromechanical transducer (mounted in the center), the main and reference Co/Rh sources, multilayered radiation shields, detectors and their preamplifiers and main (linear) amplifiers, and a contact plate and sensor. The contact plate and contact sensor are used in conjunction with the IDD to apply a small preload when it places the SH holding it firmly against the target. The electronics board contains power supplies/conditioners, the dedicated CPU, different kinds of memory, firmware, and associated circuitry for instrument control and data processing. The SH of the miniaturized Mossbauer spectrometer MIMOS II has the dimensions (5 x 5.5 x 9.5) cm and weighs only ca. 400 g. Both 14.4 keV y-rays and 6.4 keV Fe X-rays are detected simultaneously by four Si-PIN diodes. The mass of the electronics board is about 90 g [36],... 

EL with 4>el = 0.05% was observed in multilayer LB-film PLED ITO/399/A1, with a ratio in EL between the parallel and perpendicular orientations of 1.3 [523]. An even higher ratio of 2.4 was achieved in ITO/422/Ca/Al diode made from a stretch-oriented polymer film [524]. For more information on polarized LEDs, see Chapter 5 in this book. 

C. Fou, O. Onitsuka, M. Ferreira, M.F. Rubner, and B.R. Hsieh, Fabrication and properties of light-emitting diodes based on self-assembled multilayers of poly(phenylene vinylene), J. Appl. Phys., 79 7501-7509, 1996. 

O. Renault, O.V. Salata, M. Etchells, P.J. Dobson, and V. Christou, A low reflectivity multilayer cathode for organic light-emitting diodes, Thin Solid Films, 379 195-198, 2000. 

Tang CW, VanSlyke SA (1987) Organic electroluminescent diodes. Appl Phys Lett 51 913 Sun T, Wang ZL, Shi ZJ et al (2010) Multilayered graphene used as anode of organic light emitting devices. Appl Phys Lett 96 133301... 

Thin films (qv) of vitreous silica have been used extensively in semiconductor technology. These serve as insulating layers between conductor stripes and a semiconductor surface in integrated circuits, and as a surface passivation material in planar diodes, transistors, and injection lasers. They are also used for diffusion masking, as etchant surfaces, and for encapsulation and protection of completed electronic devices. Thin films serve an important function in multilayer conductor insulation technology where a variety of conducting paths are deposited in overlay patterns and insulating layers are required for separation. 

To implement this strategy, multilayered semiconductor structures were grown by MOCVD and then processed using lithographic techniques to create trenches of 10-20 p-m. Trenches of 10 pm were used to create arrays of 34 interdigitated LED/photodiode pairs, as shown in Fig. 8. As molecules adsorb onto the surfaces of these semiconducting materials, the electronic properties of the surfaces can be altered and thus changes in current can be observed when molecules such as ammonia and sulfur dioxide adsorb onto the surfaces of the diodes. 

As a conducting polymer, polyaniline has many electronics-related applications, such as rechargeable batteries (Tsutsumi et al. 1995), multilayer heterostructure light-emitting diode devices (Onoda Yoshino 1995), biosensors (Bartlett Whitaker 1987), elec-trochromic windows (Nguyen Dao 1989), and nonlinear optical materials (Papacostadi-nou Theophilou 1991). Polyaniline may be prepared from aniline by both electrochemi-... 

Figure 4.8 Schematic representation some of the elements of a generalised multilayer organic light-emitting diode (OLED) with direct addressing. The thin metallic cathode segments are connected directly to the electron-transport layer (ETL). The impermeable encapsulation is not shown.

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