Multiple Doping

Y Kawamura, S Yanagida, and SR Forrest, Energy transfer in polymer electrophosphorescent light emitting devices with single and multiple doped luminescent layers, J. Appl. Phys., 92 87-93,... 

Spray pyrolysis of ethanolic solutions of Fe(acetylacetone)3 or FeCls between 370°C and 450°C onto a glass substrate are reported for the fabrication of a-Fe20s thin-film photoanodes [75]. Upon illumination by a 150 W Xe lamp samples consistently demonstrate photocurrents of 0.9 mAcm , IPCE values up to 15%, and robust mechanical stability with no signs of photocorrosion for the undoped samples. With simultaneous multiple doping of 1% A1 and 5% Ti, an IPCE of 25% can be reached at 400 nm. Zn doping is known to induce p-type character in Ee20s thin film electrodes [76]. 

Ce in the presence of Yb and of U in the presence of Nd. These changes can be ascribed to radiationless-energy transfer between the ions. There are also some additional smaller variations in decay times, such as the decrease of the Yb mean life in the presence of U. These are probably associated with alterations in the crystalline field caused by the multiple doping. 

To answer questions regarding dislocation multiplication in Mg-doped LiF single crystals, Vorthman and Duvall [19] describe soft-recovery experiments on <100)-oriented crystals shock loaded above the critical shear stress necessary for rapid precursor decay. Postshock analysis of the samples indicate that the dislocation density in recovered samples is not significantly greater than the preshock value. The predicted dislocation density (using precursor-decay analysis) is not observed. It is found, however, that the critical shear stress, above which the precursor amplitude decays rapidly, corresponds to the shear stress required to disturb grown-in dislocations which make up subgrain boundaries. 

A variety of colors, such as green, amber, and red (and infrared), can be obtained with different semiconductor materials without the need for a filter (see Ch. 13, Table 13.4). A LED (or photodiode) device may consist of multiple diodes in an array operating in the reverse-bias mode. Patterns of light showing symbols, letters, or numbers can thus be produced with different colors obtained by doping the semiconductor material by CVD or ion implantation. 

Karas BR, Strickert HH, Schreiner R, EUis AB (1981) Luminescent photoelectrochemical cells. 5. Multiple emission from teUurium-doped cadmium sulfide photoelectrodes and implications regarding excited-state communication. J Am Chem Soc 103 1648-1651... 

The fabrication and characterization of a fiber optic pH sensor based on evanescent wave absorption was presented by Lee63. The unclad portion of a multi-mode optical fibre was coated with the sol-gel doped with pH sensitive dye. The sensitivity of the device increased when the multiple sol-gel coatings were used in the sensing region. The dynamic range and the temporal response of the sensor were investigated for two different dyes -bromocresol purple and bromocresol green. 

Except when alloys or highly doped samples are being considered, it leads to a lack of multiplicity in the NMR peaks, even for inherently oriented single crystals, because of the presence of one unique atom of each element in the unit cell. 

The third member, trimethylenemethane (3), had some relevance to our studies on carbenes, since besides methylene and its simply substituted derivatives trimethylenemethane 3 is one of the few molecules having a triplet ground state.22 Also the experience with 3 could be of help in order to deal with the singlet/triplet differentiation in matrix-isolated carbenes. We learned that, if the calculated IR spectra of the singlet and triplet molecule are sufficiently different, it might be possible to determine the multiplicity of the matrix-isolated species by comparison with the experimental IR spectrum. In this context it is also worth mentioning that we were able to measure the matrix IR spectrum of 3, but a special technique (irradiation in halogen-doped xenon matrices) had to be developed in order to achieve a concentration of 3 sufficient for its IR detection.23... 

---