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In this paper, we will discuss stability and reliability requirements of organic electronic devices and evaluate different encapsulation approaches enabling stable organic ultra-thin and stretchable devices. We highlight the differences in requirements and encapsulation approaches for applications, including organic light emitting diode (OLED) displays, OLED lighting, photovoltaics, and sensors. Stability and reliability requirements addressed in this paper cover light management, mechanical characteristics, chemical compatibility, form factors, and durability. While flexible organic electronic devices have already been demonstrated and commercialized, so far only prototypes of ultra-thin and stretchable devices have been demonstrated. The technological progress is promising and by identifying the gaps between prototyping and product realization, we intend to stimulate further research and development in this area.

Aims of the present investigation were: (i) to assess the prevalence of current smokers and relative smoking status among a large number of heroin addicts attending opioid-substitution therapy prevalence; (ii) to evaluate the relationship between the type (methadone, buprenorphine) and dosage of opioid substitution therapy and nicotine dependence. Three hundred and five (305) heroin addicts under opioid-substitution therapy were recruited at five Addiction Units. All participants completed a questionnaire assessing sociodemographic information, type and dose of opioid-substitution therapy, smoking history and status, Fagerström Test for Nicotine Dependence (FTND), and the Zung Self-Rating Depression scale (SDS). 298 subjects, out of 305 (97.2%) were smokers, with an average of 20.5 cigarette/day and a median FTND of 6. Our data confirmed the high prevalence of smokers among heroin addicts, the highest described in the literature to date among heroin addicts under substitution therapies, without any significant difference between methadone vs. buprenorphine therapy groups. There was no correlation between dose of methadone or buprenorphine and average number of cigarettes/day. Patients in substance abuse treatment very frequently smoke cigarettes and often die of tobacco-related diseases. Substance abuse treatment programs too often ignore tobacco use. We hope that these findings will help to incorporate smoking cessation in substance abuse treatments.

Among the emerging techniques able to reveal the metals contaminating the wafer surface in the manufacturing processes of microelectronic devices, time-of-flight secondary ion mass spectrometry (ToF-SIMS) is considered very promising. Despite the potentialities of this analytical tool, some of the phenomena that affect the signal intensity are not fully investigated and still hinder the use of the technique. To evaluate the capabilities of ToF-SIMS to detect quantitatively metal traces on silicon wafers, we analyzed contaminated reference samples produced by spin coating. These standards were also characterized by total reflection x-ray fluorescence spectroscopy (TXRF), x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The comparison between results obtained by TXRF and ToF-SIMS allowed us to evaluate the metal detection sensitivities and to estimate the detection limits for most of the elements that produce detrimental effects on device yield. We prove that the metals' secondary ion yields are governed by silicon oxide matrix effects and that a linear relationship between the ToF-SIMS signal intensity and the elemental areal density holds for most of the considered elements for changes in the uppermost layer composition ranging over more than three orders of magnitude. Besides, it is shown that although spin-coating is commonly employed to produce reference samples, the lateral distribution and the physical status of the contaminants produced by this technique may seriously affect the results obtained by both ToF-SIMS and TXRF.

Silicon carbide films on silicon have been grown by annealing of pre-deposited C60 film on silicon at T = 900°C for 300 min. C60 molecules are confined on the surface during annealing by a non-volatile carbon layer produced by irradiation of the C60 film with an ion gun (Ar+ or Ga+). During annealing the C60 film confined in the irradiated areas forms SiC while the remaining C60 evaporates off. These results introduce a new method of direct patterning SiC structures on Si with submicron resolution.

We describe encapsulated passive matrix, video rate organic light-emitting diode (OLED) displays on flexible plastic substrates using a multilayer barrier encapsulation technology. The flexible OLED (FOLED™) displays are based on highly efficient electrophosphorescent OLED (PHOLED™) technology deposited on barrier coated plastic (Flexible Glass™ substrate) and are hermetically sealed with an optically transmissive multilayer barrier coating (Barix™ encapsulation). Preliminary lifetime to half initial luminance (L0∼100 cd/m2) of order 200 h is achieved on the passive matrix driven encapsulated 80 dpi displays; 2500 h lifetime is achieved on a dc tested encapsulated 5 mm2 FOLED test pixel. The encapsulated displays are flexed 1000 times around a 1 in. diameter cylinder and show minimal damage.

Thin film polycrystalline solar cells on low cost substrates offer an attractive path to large scale production of solar cells with the potential to generate electricity at 1$/W. SRI International has a propriety technology to deposit Si films in a reactor based on fluidized bed technology. The results presented in this paper show that, with a proper reactor design, Si films can be grown at rates of 7 μm/min and higher. Films are crystalline, with crystallite sizes higher than 20 μm. We have also evaluated the performance of SiO 2 diffusion barriers as a potential way towards the use of low cost substrates, such as metallurgical grade Si. Whereas SiO 2 layers of 0.1 μm are not sufficient to stop P diffusion from the substrate to the film, 0.7 μm layers are thick enough to accomplish this goal. The reactor configuration can be used for continuous and integrated cell/panel fabrication. At present we are building a first continuous reactor, and in this paper we present some preliminary considerations.

To meet increasing demand for electrical power using solar photovoltaics, millions of tons of solar-grade silicon costing 4 gas—an exothermic, fast, and complete reaction. SRI International routinely uses reactors that can produce at rates >20 metric tons per year (mty), and has licensed the technology to several companies. The Si product is completely separated from the by-product NaF by leaching or melt separation. With the direct use of industrially available Na, B and P levels in the Si product are 100 Ω·cm when purified reactants were used. The purity, electronic parameters, and solar cell efficiency of 15% indicate that this silicon is of solar grade and can be a key contributor in developing solar power markets.

More than 90% of commercial solar cells are produced using mono- and poly-crystalline silicon, with estimated about 15,000 MT of silicon feedstock used in 2008. Future silicon use is estimated to grow proportionally with the solar industry (30%/y). Substantial amounts of highly refined polycrystalline silicon material are wasted in the final stages of producing ingots and in wafer slicing. Recycling of wasted silicon in the form of fines generated in deposition reactors and in slicing operation can lower the production cost of solar-grade silicon feedstock to less than $10/kg, and substantially shorten energy payback time. The SRI International developed technology is based on the prepurification and simultaneous melt-consolidation and further purification of silicon fines from wafering operations. The consolidated product in form of granules and ingots with a resistivity range of 1 to 5 Ω·cm can be used in the melt growth of both single-crystal and polysilicon ingots for use in photovoltaic cells.

Solar industry growth and a silicon feedstock shortage have spurred interest in thin silicon film photovoltaic (PV) technology. To reduce PV panel and electricity cost, technologies are needed with high deposition rates of high-quality Si film, scalability to large areas and integrated cell and panel fabrication. A new SRI International deposition technology based on fluidized bed reactor-chemical vapor deposition (FBR-CVD) takes advantage of the high heat and mass transfer in a FBR, and combines it with subhalide CVD chemistry with highly reactive species created in the reactor. The SRI's FRB design minimizes boundary layer thickness to achieve deposition rates as high as several microns per minute and good coating uniformity. The resulting silicon films are highly crystalline with 10–100 µm grain sizes over 5 cm2; with in-depth homogeneous resistivity, typically 0.1–5 Ω·cm, but up to 1000 Ω·cm obtained under some deposition conditions; and with bulk diffusion length >200 µm. The reactor configuration can be used for continuous and integrated cell/panel fabrication.

Scanning surface analysis by laser ionization (SALI) has been developed to provide chemical images of surfaces. SALI is a recently developed technique that uses nonselective photoionization of sputtered or desorbed neutral atoms and molecules emitted from a sample close to but above (~ 1 mm) the surface, followed by time-of-flight mass spectrometry (TOF-MS). In this new development, specifically nonresonant multiphoton ionization (NRMPI) and sputtering using a field-emission liquid-metal ion gun are employed. The reason for decoupling the sputtering and ionization is that in nearly all situations, the neutral particles constitute the dominant channel for the sputtered material; therefore, SALI is much less sensitive than scanning secondary ion mass spectrometry (SIMS) to changes in the chemical matrix, and also SALI delivers a much more uniform sensitivity between different species than SIMS. Furthermore, the mass multiplex advantage of TOF-MS allows an entire mass spectrum of the sample to be mapped out in one scan of the surface. Initial results with a transmission electron microscopy (TEM) grid and an electronic device are presented.

The effect of multilayer barrier materials on the lifetime of organic photovoltaic cells has been investigated. For thin film encapsulated cells a protective layer was used to prevent damage during barrier layer deposition. No post deposition effects developed after dry box storage. In accelerated temperature and humidity lifetime testing the degradation of the encapsulated cells can be related to the loss of effective cell area. An extrapolation of the lifetime at room conditions has been quantitatively determined by comparing the cell degradation with the loss of Ca in a Caoxidation test. The results indicate a barrier permeation rate of 10 -4 gr /[m 2 * day] for these samples, corresponding to a lifetime of greater than 5000 hours. Routes to improvement of the OPV cell lifetime are discussed.

Reaction of C60 with Si at temperatures above 800°C is known to give SiC. Furthermore, treatment of vapor-deposited C60 films with a beam of Ar+ transforms the surface layer of C60 into a nonvolatile carbon deposit. Based on these two findings, we have developed a method for patterning SiC structures on silicon. C60 is first vapor deposited onto a clean Si surface. By rastering the ion beam on selected parts of the sample, we write a chosen pattern on the C60 film. Upon increasing the temperature to around 300–350°C, the C60 film remains only in the areas that were subjected to irradiation, while it evaporates off the remaining surface. During the subsequent annealing at 900°C, the modified C60 layer confines the underlying C60 on the silicon surface, allowing the formation of SiC. At shorter times, traces of the capping layer are visible at the edges of the irradiated zone. These results demonstrate the principle of fabricating lithographically patterned SiC structures on silicon without masking and etching processes and with the high lateral resolution possible with ion beams.

OLEDs are an ideal technology for electronic display applications. They are fabricated by depositing very thin films of organic materials at low temperatures (

Thin film barrier coatings for protecting Organic Light Emitting Diode (OLED) displays against the environment are extremely difficult to fabricate. The coatings must have extremely low water/oxygen permeability, no defects, cover several microns of topography, and be applied at temperatures below 100°C in a process that does not compromise the performance of the display. Vitex Systems has succeeded in depositing such coatings using an organic/inorganic, thin film multilayer structure termed Barix encapsulation. In this paper results on encapsulation of OLED test pixels and passive matrix displays will be shown. Lifetime and permeability tests conducted at high temperature and humidity demonstrate that this thin film coating can meet the necessary performance requirements for commercial OLED displays. Processing parameters, layer architecture and manufacturing techniques are analyzed and discussed. Thin film encapsulated displays are used to demonstrate the utility of the encapsulation technique.

At present flexible electronic devices are under extensive development and, among them, flexible organic light-emitting diode displays are the closest to a large market deployment. One of the remaining unsolved challenges is high throughput production of impermeable flexible transparent barrier layers that protect sensitive light-emitting materials against ambient moisture. The present studies deal with the adaptation of the atomic layer deposition (ALD) process to high-throughput roll-to-roll production using the spatial ALD concept. We report the development of such a process for the deposition of 20 nm thickness Al2O3 diffusion barrier layers on 500 mm wide polymer webs. The process uses trimethylaluminum and water as precursors at a substrate temperature of 105 °C. The observation of self-limiting film growth behavior and uniformity of thickness confirms the ALD growth mechanism. Water vapor transmission rates for 20 nm Al2O3 films deposited on polyethylene naphthalate (PEN) substrates were measured as a function of substrate residence time, that is, time of exposure of the substrate to one precursor zone. Moisture permeation levels measured at 38 °C/90% relative humidity by coulometric isostatic–isobaric method were below the detection limit of the instrument (

Irradiation of vapor-deposited C60 films with a KeV ion beam (Ar+ or Ga+) transforms the surface layer of C60 into a non-volatile carbon film. During the subsequent annealing at 900°C, the modified C60 layer confines the underlying C60 on the silicon surface, allowing the formation of SiC. With this method, patterned SiC structures on silicon with the high lateral resolution possible with ion beams are fabricated

The mass spectral fragmentation of l-tryptophan has been investigated as a function of desorption technique and photoionization method using 7 keV Ar+ static sputtering, 355 nm pulsed laser-induced desorption, and thermal desorption at 150 to 200 degree(s)C in conjunction with 118 nm (10.49 eV), 266 nm (4.66 eV), and 355 nm (3.50 eV) laser positionization. In addition, ion-stimulated desorption of neutrals has been compared with positive secondary ion data. Molecular fragmentation is dominated by the internal energy contribution of the desorption process rather than photoionization method; fragmentation is maximal with ion-stimulated desorption and minimal with thermal desorption. Furthermore, single-photon ionization with 118 nm generally results in less fragmentation than multiphoton ionization (MPI). Finally, the effect of laser pulse width on the 266 nm MPI of thermally-desorbed neutral species has been explored. The use of 35 ps rather than 5 ns laser pulses at 266 nm has been explored. The use of 35 ps rather than 5 ns laser pulses at 266 nm has been found to cause a decrease in the molecular fragmentation of l-tryptophan. These results have implications for the surface analysis of labile organic compounds.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Praseodymium endohedral fullerenes have been produced in a graphite arc discharge system and shown to exist in the entire fullerene series from C60 to C100. These endohedrals prefer to be encaged in the larger fullerenes which exist in concentrations approximately equal to the concentrations of their empty counterparts. However for C60 and C70 the endohedrals are only about 5% of their counterparts. Solvent extraction with regular fullerene solvents is partially successful for Pr@C82 but completely unsuccessful for the other endohedrals. However, these Pr endohedrals appear to be stable to air and solvent exposure over long periods of time.

The determination of the lateral distributions of chemical species on surfaces is of constantly increasing technological importance in many applications, such as integrated circuit manufacturing. The only two tools which have been available are scanning Auger electron spectroscopy (AES) and secondary ion mass spectrometry (SIMS) (in scanning or microscope modes). The AES technique is the most widespread but generally is considered to be of lesser sensitivity than SIMS, at least for spatial resolutions (defined by the primary beam diameter, d) of approximately ≥ 0.1 µm. Nominal sensitivities for AES are ~2 to 3% concentrations for d ≥1 µm, and 3 to 10 % for d ranging from 1.0 µm to 0.1 µm, respectively.1 Also, scanning AES can be very problematic for insulators and electron sensitive materials, although it undoubtedly will continue to be a major tool.

We demonstrate full color, top emission, active matrix OLED displays on flexible stainless steel substrates. The 100 dpi QVGA displays are driven by LTPS TFT backplane with excimer laser annealed poly-Si. To our knowledge this is the world's highest resolution full color flexible AMOLED display on steel foil demonstrated to date. Encapsulation is by a multilayer thin film.

In this work a systematic comparison of total reflection X-ray fluorescence (TXRF), synchrotron radiation-TXRF (SR-TXRF), time of flight secondary ion mass spectroscopy, lifetime, and deep level transient spectroscopy data of iron concentration is carried out. SR-TXRF is considered as a reference for the other techniques. Reasonably good correlations are obtained, though, as expected, SR-TXRF exhibits the maximum sensitivity among surface techniques. Among lifetime measurements, the electrolytic metal analysis tool (ELYMAT) technique shows the best sensitivity at very low concentrations. A method is developed to elaborate ELYMAT data in order to quantify iron concentration when more contaminants are simultaneously present.

Fully encapsulated passive matrix, video rate, phosphorescent OLED displays on flexible plastic substrates using a multilayer barrier encapsulation technology are described. The flexible OLED (FOLED™) displays are based on highly efficient electrophosphorescent OLED (PHOLED™) technology deposited on barrier coated plastic film (Flexible Glass™ substrate) and are hermetically sealed with an optically transmissive multilayer barrier coating (Barix™ Encapsulation). Preliminary lifetime to half initial luminance (Lo∼100 cd/m2) of order 200 h is achieved on the encapsulated 80 dpi displays using a passive matrix drive at room temperature; 2500 h lifetime is achieved on a dc tested encapsulated 5 mm2 FOLED test pixel. The encapsulated displays are flexed 1000 times around a 1″ diameter cylinder and show minimal damage.