Low-threshold organic semiconductor

One possibility to realize low-threshold organic solid-state lasers is to utilize guest-host systems. In the following this is demonstrated for the example of DCM- and DCM2-doped organic semiconductors. As host materials the electron-transport material Alq3 and the hole-conducting materials NPD and CBP are used. 

The device with interdigitated drain and source contacts of 46.8 cm channel width and of 20 pm channel length, characterised at ambient atmosphere, could drive drain currents of about -6.8 mA directly after the pentacene deposition under ambient atmosphere = 23400). The on-off ratio reached a value of 10" and the threshold voltage was 12.3 V. After that the sample was encapsulated by a 1.5 pm thick Teflon layer. To avoid damage of the organic semiconductor, a low deposition rate of 21 nm/min was selected by a thickness gradient of less than 10% [19]. 

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