Browsing by Author "Chou, C. H."

Now showing 1 - 3 of 3

Fabricating a n(+)-Ge contact with ultralow specific contact resistivity by introducing a PtGe alloy as a contact metal
(2015-09-14)
Hsu, C. C.
;
Chou, C. H.
;
Wang, S. Y.
;
Chi, W. C.
;
Chien, C. H.
In this study, we developed an Ohmic contact structure to an in situ n(+)-Ge film that has an ultralow specific contact resistivity of [(6.8 +/- 2.1) x 10(-8) Omega.cm(2)]. This structure was developed by introducing a PtGe alloy as the contact metal. We observed that Ohmic contact behavior can be achieved with several other metals, and the contact resistance is related to the work function of the metal. A physical model of the band diagram was created for the Schottky tunneling width, which can provide insight into the validation and explanation of work function-dependent specific contact resistivity. Dopant segregation at the interface and increased interface roughness induced by the formation of the alloy are crucial in further reducing the specific contact resistivity. As a result, a stable PtGe alloy and high doping concentration in Ge are critical in pursuing a lower contact resistance for a Ge n-channel device. (C) 2015 AIP Publishing LLC.
Fabricating a n(+)-Ge contact with ultralow specific contact resistivity by introducing a PtGe alloy as a contact metal (vol 107, 113503, 2015)
(2015-12-07)
Hsu, C. C.
;
Chou, C. H.
;
Wang, S. Y.
;
Chi, W. C.
;
Chien, C. H.
Investigations of organic light emitting diodes with CdSe(ZnS) quantum dots
(2008-02-15)
Lee, C. W.
;
Chou, C. H.
;
Huang, J. H.
;
Hsu, C. S.
;
Nguyen, T. P.
In this study, we report results on investigation of bilayer light emitting diodes made of organic capped CdSe(ZnS) core/shell type nanocrystals and poly [2-phenyl-3-(9,9-dihexyl-fluoren-2-yl) phenylene vinylene]-co-[2-methoxy-5-(2'-ethylhexyloxy) phenylene vinylene] (FP-PPV-co-MEH-PPV) electroluminescent co-polymer. Light emitting diodes of structure: indium-tin-oxide (ITO)/polyethylene dioxythiophene: polystyrene sulfonate (PEDOT:PSS)/FP-PPV-co-MEH-PPV/Ca/Al devices have been fabricated and studied. The co-polymer device emits a yellow light with a maximum brightness of 3949 cd/m(2) and a maximum external quantum efficiency of 0.27 cd/A at 10 V. Incorporation of CdSe(ZnS) quantum dots into the active polymer film resulted in an increase in device brightness, which reached 8192 cd/m(2) and in external quantum efficiency, which became 1.27 cd/A at 7 V with a lower turn-on voltage. The results indicate that CdSe(ZnS) quantum dots improved significantly the emission of the devices by modifying the injection and transport of the charge carriers. We suggest a non-uniform dispersion of QDs in the co-polymer layer with carrier blocking process by the particles, which produced a balanced charge distribution inside the co-polymer, and thus increased the emission efficiency. (c) 2007 Elsevier B.V. All rights reserved.