Light device architecture

Vapor-Deposited Organic Light-Emitting Device Architectures.529... 

VAPOR-DEPOSITED ORGANIC LIGHT-EMITTING DEVICE ARCHITECTURES... 

Other device architectures include inverted OLEDs. Here the cathode is in intimate contact with the substrate. The organic layers are then deposited onto the cathode in reverse order, i.e., starting with the electron transport material and ending with the HIL. The device is completed with an anode contact. In this case, as above, one of the electrodes is transparent, and light exits from the device through that contact. For example, Bulovic et al. [38], fabricated a device in which Mg/Ag was the bottom contact and ITO the top electrode. The advantage of this type of architecture is that it allows for easier integration with n-type TFTs (see Section 7.5 for a discussion of active-matrix drive OLED displays). 

Figure 7.5 shows a schematic example of the electroluminescent process in a typical two-layer OLED device architecture. When a voltage is applied to the device, five key processes must take place for light emission to occur from the device. 

Light emission Light is observed from photons that exit the OLED structure. Typically many photons are lost due to processes such as total internal reflection and selfabsorption of the internal layers [71]. In typical bottom-emitting device architectures, only 20-30% of the photons created exit the device through the front of the substrate. 

If a p-i-n (i.e., LEC) device architecture is used, the choice of the ionic dopant and surfactant additives to the light-emitting organic ink are critical to the print uniformity and resulting device performance and stability. The ionic dopants have limited solubility and can prematurely fall out of solution during the printing process. Most of the previous works in... 

Table 3 Device architecture and performance of light-emitting diodes with PAE emitting layer... 

Light-Emitting Electrochemical Cell Device Architecture. 170... 

Substrate configuration — Terminology used in - photovoltaic devices to designate the device architecture in which the light enters the device through the top face of the cell, i.e., oppositely to the substrate. 

FIGURE 2.3.1 (a) Schematic diagram of top-gate OFET using a standard TFT device architecture. (b) Output characteristics of state-of-the-art, unencapsulated OFET measured in air and light (closed symbols = device measured after manufacture open symbols = device measured two weeks later). 

OLED Materials and Device Architectures for Full-Color Displays and Solid-State Lighting... 

Device architectures of white OLEDs using phosphorescent emitters can be similar to the architectures described in Section 14.3.5. The white color can be generated by the simultaneous emission of light from multiple emitters in... 

Ir complexes were also used to develop white OLEDs (WOLEDs) for large-scale production of solid-state light sources and backlights in liquid-crystal displays. Several device architectures have been introduced to achieve high brightness and efficiency in WOLEDs. By controlling the recombination current within individual... 

In a number of studies, others and we have demonstrated that the performance of PSCs depends critically on the nanoscale organization and fimctionaUty of the photoactive layer, the interfaces with and type of the charge collecting electrodes, and the overall device architecture. For the last one, device performance can be improved, for example, by applying hole blocking layers [73], optical spacers to enhance light absorption in the layer of the same thickness [74, 75], and by using the tandem cell architecture [76-78], where two printable photovoltaic cells are added in series. In a tandem cell, it is possible to combine two, or more, thinner... 

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