OLEDs applications

The upper limit for passive matrix OLEDs thus depends on many factors, including the reverse current of the diodes, the current delivery of the row drivers, the roll-off in OLED power efficiency, and the brightness and contrast ratio requirements of the application. The practical limit is probably less than VGA resolution (480 rows by 640 x 3 columns, where the factor of 3 reflects the RGB subpixels for color) for power-sensitive portable applications. However, such considerations are less important where a wall-plug is available and one company in Japan (Idemitsu Kosan [190]) has demonstrated full color television using passive OLED arrays. 

Active matrix drive schemes make OLEDs potentially competitive over a much wider range of applications. There is no longer a strict limit on the number of pix-... 

Indicator lights, fixed pattern, and segmented displays are applications which have been suggested for OLED deployment. Manufacturers of automobile components have shown interest in OLED indicators for the dashboard, where the primary considerations are those of cost, form factor, brightness, and stability over a wide range of ambient conditions. Power consumption is not particularly critical. The possibility of molding a thin light into a curved dashboard is attractive. 

Yersin H (2004) Triplet Emitters for OLED Applications. Mechanisms of Exciton Trapping and Control of Emission Properties. 241 1-6 Yeung LK,see Crooks RM (2001) 212 81-135... 

As a class of n-type organic semiconductors, PBI derivatives have received considerable attention for a variety of applications [312, 313], for example, for organic or polymer light-emitting diodes (OLEDs and PLEDs) [314, 315], thin-film organic field-effect transistors (OFETs) [316, 317], solar cells [318, 319], and liquid crystals [320]. They are also interesting candidates for single-molecule device applications, such as sensors [321], molecular wires [322], or transistors [141]. 

In electroluminescent applications, electrons and holes are injected from opposite electrodes into the conjugated polymers to form excitons. Due to the spin symmetry, only the antisymmetric excitons known as singlets could induce fluorescent emission. The spin-symmetric excitons known as triplets could not decay radiatively to the ground state in most organic molecules [65], Spin statistics predicts that the maximum internal quantum efficiency for EL cannot exceed 25% of the PL efficiency, since the ratio of triplets to singlets is 3 1. This was confirmed by the performance data obtained from OLEDs made with fluorescent organic... 

As mentioned in this review, AMPLEDs are especially attractive for motion picture applications. The Pay-Per-View effect in OLED displays reduces power consumption and extends operation lifetime. Motion picture applications also minimize image retention and optimize display homogeneity. AMOLED has been widely viewed as a promising display technology in competing with AMLCD and plasma displays. The dream of using organic semiconductor films for optoelectronic device applications has become a reality. 

M Leadbeater, N Patel, B Tierney, S O Connor, I Grizzi, and C Towns, Blue LEP-OLED with 30,000 hours lifetime for flat panel display applications, SID Digest Tech. Pap., 35 162-163, 2004. 

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