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A blue organic light-emitting diode employing perylene as light emitting dopant and 9,10-bis(3’5’-diaryl)phenyl anthracene (DPA) as host has been studied for its decay mechanisms. The device structure is ITO(indium tin oxide)∕CuPc(copper phthalocyanine)∕NPD(α-naphthylphenylbiphenyl diamine)∕DPA:perylene∕Alq3 (8-hydroxy-quinoline aluminum)∕MgAg. In this device, CuPc and NPD are used as hole injection and transporting layers, DPA as a blue host, perylene as a blue emitting dopant, Alq3 as an electron transport layer, MgAg as cathode, respectively. A luminance of 4359cd∕m2 at 15V and a current efficiency of 3cd∕A at 5V have been achieved. The breakdown of the interfaces in the device is found to be one of the factors for the decay and the decomposition of the light emitter is not significantly studied by current–voltage–luminance, photoluminescence, and electroluminescence measurements. The lifetime is not intrinsic for this type of device.

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The authors have investigated the edge emission of microcavities which are formed by low-molecular organic light emitting diodes sandwiched between dielectric mirrors and the metal cathode. The edge emission relative to the surface emission is found to significantly depend on the layer number of alternating high and low refractive index films in dielectric mirrors. The enhancement of cavity devices can reach a factor of ~3.0 compared with noncavity devices. Spectra of organic film pumped by edge emission of microcavity devices have been observed, a mechanism of achievement of an amplified spontaneous emission has been discussed theoretically.

Ni-doped Ge-Te (Ni-GT) material was proposed and investigated for phase change random access memory (PCRAM) applications. With Ni addition, the crystallization temperature, data retention ability and crystallization speed were obviously improved. The surface roughness of crystalline Ni-GT films was decreased by Ni incorporation. Moreover, temperature dependent transmission electron microscopy (TEM) was applied to investigate the phase change behavior of Ni-GT films. All the experimental results demonstrated that Ni-GT material has potential for high-speed PCRAM applications in high temperature environment.