Aluminium organic semiconductors

To address this problem we have prepared highly crystalline films of the organic semiconductor DIP and capped them with r.f magnetron sputtered aluminium oxide films. 

Polymers from Thiophen Derivatives.—The bifunctionality of thiophen and its potential availability in large quantities at a low price has for many years attracted the interest of polymer chemists. However, progress has been slow. 2,5-Dichlorothiophen has been polymerized to a solid in 93% yield on treatment with aluminium chloride and cupric chloride in carbon disulphide. The product is believed to be poly-5-chloro-2,3-thienylene. Thiophen-2,5-dicarboxylic hydrazide was prepared by the reaction of thiophen-2,5-dicarbonyl chloride with the corresponding dihydrazide and then cyclodehydrated to poly-(thienylene-[2,5]-alt-l,3,4-oxadiazolylene-[2,5]-amer) (258) by polyphosphoric acid. This polymer could also be obtained directly from thiophen-2,5-dicarboxylic acid and hydrazine in oleum. The polymers produced were investigated in view of their thermal stability and as polymeric organic semiconductors. The same research... 

Among other organic reagents, Ga has been determined with Chrome Azurol S in aluminium, aluminium chloride, and peat bath [62], with Xylenol Orange in biological samples [63], with PAR in aluminium and its alloys [64], with haematoxylin in aluminium alloys [55], with Carminic Acid in gallium arsenide semiconductor materials [65], and with Semimethylthymol Blue in minerals and ores [66]. 

Rather little work has been reported on the use of conducting polymers in active semiconductor devices. A problem in organic pn-junctions is the interdiffusion of dopants destroying the abrupt interface. In Schottky junctions made of (the more stable) p-type polymers, metals with low work functions must be used. These metals, such as aluminium (work function 4 3 eV) are typically reactive and oxidize easily. 

In organic electroluminescent devices, the semiconductor layer is sandwiched between two electrodes, as shown in Fig. 10a. One electrode, such as gold (Au) or indium tin oxide (ITO), is chosen to have a high work function, for injection of positive charges (holes). The other electrode, often aluminium (Al), calcium (Ca) or... 

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