Browsing by Author "Liu, XY"

Now showing 1 - 2 of 2

Influence of dislocation density on photoluminescence intensity of GaN
(2005-05-01)
Falth, JF
;
Gurusinghe, MN
;
Liu, XY
;
Andersson, TG
;
Ivanov, IG
The influence of dislocation density on photoluminescence intensity is investigated experimentally and compared to a model. GaN samples were grown by molecular beam epitaxy and metal-organic chemical vapour deposition. Different growth parameters and thicknesses of the layers resulted in different dislocation densities. The threading dislocation density, measured by atomic force microscopy, scanning electron microscopy and X-ray diffraction, covered a range from 5 x 10(8) to 3 x 10(10) cm(-2). Carrier concentration was measured by capacitance-voltage-, and Hall effect measurements and photoluminescence at 2 K was recorded. A model which accounts for the photoluminescence intensity as a function of dislocation density and carrier concentration in GaN is developed. The model shows good agreement with experimental results for typical GaN dislocation densities, 5 x 10(8)-1 x 10(10) cm(-2), and carrier concentrations 4 x 10(16)-1 x 10(18) cm(-3). © 2005 Elsevier B.V. All rights reserved.
Strain-induced very low noise RF MOSFETs on flexible plastic substrate
(2005)
Kao, HL
;
Chin, A
;
Hung, BF
;
Lai, JM
;
Lee, CF
Using microstrip line design to screen substrate resistance generated RF noise, very low 1.1 dB min. noise figure (NFmin) and high 12 dB associate gain are measured at 10 GHz of 0.18 mu m MOSFET on plastic without de-embedding. The die on plastic was thinned to 30 mu m that allows applying uniaxial strain to further lower the 10 GHz NFmin to only 0.92 dB and comparable well with the 0.13 mu m and 90nm nodes MOSFETs.