In order to improve the running durability of organic electroluminescent devices (OELDs), the doping sites of molecular OELDs were optimized, and the frequency responses of the optimized devices were examined for Mg-In/bis (10-hydroxybenzo[h]quinolinate) beryllium (BeBq2)/N, N'-diphenyl-N, N'-(3-methylphenyl)-1, 1'-biphenyl-4, 4'-diamine (TPD)/4, 4', 4"-tris (3-methylphenylphenylamino) triphenylamine (MTDATA)/ITO. The TPD hole transport layer was the optimum doping site for 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) dopant, and a very high efficiency of 13 cd/A at 0. 13 kcd/m2 was obtained for yellow emission. Half-decay times under a constant direct current density of 1. 0 mA/cm2 from an initial luminance of 0. 13 kcd/m2 extended to longer than 26,000 hours. The luminance of the optimized device decreases lineally with respect to the logarithm of the frequency as the frequency increases in the range from 1 kHz to 0. 3 MHz when a square wave with a duty ratio of 50% and a maximum voltage of 5.0 V is applied. A new driving method involving frequency modulation is proposed. This may offer accurate control of pixel luminance, and enable simple driving circuits adapted to highly integrated digital LSI chips, or the concept of system on glass.

The transport properties of low energy quasi-particles across the base layer in superconducting base transistors has been described using the Boltzmann equation which is based on the BCS theory. In order to investigate these transport properties, the Boltzmann equation was solved by means of the Monte-Carlo method which includes the acoustic phonon scattering mechanism. For the isotropic Nb system at 3 (K), a large mean-free path of L6.710-2 (cm) and a diffusion coefficient of D2.5105 (cm/s) were obtained. The base layer transit time was estimated to be about 0.3 (ps) for a 1000 () thin Nb base at 3 (K). We also applied this method in the case of the oxide high-Tc superconductor YBa2Cu3O7, by modifying the corresponding parameter value.