High electron mobility detection

Figure 1. Schematic of the detection system at a radio telescope using an SIS (superconducting-insulating-superconducting) mixer and a HEMT (high electron mobility transistor) amplifier. Here v ky is the sky frequency, Vio ibe local oscillator frequency, and Vif is the intermediate frequency.

Kang, B., Pearton, S., Chen, X, Ren, E, Johnson, J.,Therrien, R., Rajagopal, P, Roberts, X, Finer, E. and Linthicum, K. (2006) Electrical detection of deoxyribonucleic acid hybridization with AlGaN/GaN high electron mobility transistors , App//ed Physics Letters, 89(12). 

Kang, B., Ren, E, Wang, L., Lofton, C., Tan, W., Pearton, S., Dabiran, A., Osinsky, A. and Chow, P. (2005e) Electrical detection of unmobilized proteins with imgated AlGaN/GaN high-electron-mobility transistors AppZ/ed Physics Letters, 87(2). 

In liquids with sufficiently high electron mobilities, the ionization electrons produced in the track of an individual particle or quantum can be detected separately. An advantage of this method is the fact that once the ionization electrons have escaped into the bulk of the liquid, no losses due to volume recombination with positive charge carriers occur. A disadvantage is, however, that electron attachment to electronegative impurities influences the electron signal. This is the foimdation of the application of liquids in electron pulse chambers (see Section 9.2). 

It was found that 368 exhibits ambipolar activity with appreciable electron (0.12 cm2 V 1 s ) and hole (0.008 cm2 V 1 s-1) mobilities at the substrate growth temperature of 70°C, and 371 shows monopolar n-type activity with a high mobility of 0.32 cm2 V-1 s-1 for semiconducting films deposited at a substrate temperature of 25°C. 373 exhibits stable n-type activity even in the air although the observed electron mobility in the air (0.01 cm2 V-1 s ) is somewhat lower than that under vacuum (0.08 cm2 V-1 s-1). In the case of 368 films grown at 70°C, both n- and p-type mobilities as well as current on-off ratios are enhanced by orders of magnitude compared to films grown at 25°C. 369 exhibits only p-type activity, with no detectable n-type behavior. Hole mobility extracted from the transfer plot is 5 x 10-14 cm2 V-1 s 1 with... 

Polysilanes are air-stable Si-Si backbone polymers that exhibit efficient emission in the UV spectral region, high hole mobility, and high nonlinear optical susceptibility [28]. These properties arise from delocalization of a electrons along the Si-Si chain. Polysilanes have been employed as fluorescent materials for radiation detection, as electroluminescent materials for display devices, and as photorelractive materials for holographic data storage [28]. 

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