Browsing by Author "Chen, TH"

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5 mm high-power-density dual-delta-doped power HEMT's for 3 V L-band applications
(1996-05-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Chen, TK
;
Liu, TH
A high-power-density dual-delta-doped AlGaAs/InGaAs/GaAs high electron mobility transistor (HEMT) for personal communication applications has been developed. A 5.0 mm gate-width device operating at a drain bias of 3.0 V gave an output power over 1 W, The 1 mu m gate-length HEMT exhibited a current density of 425 mA/mm at V-gs = 0.5 V, The maximum transconductance of the device was 270 mS/mm, The effective knee voltage was as low as 0.3 V, At the class AB operation, the HEMT demonstrated an output power density of 200 mW/mm, 64% power-added efficiency and 18.2 dB linear gain at 900 MHz, This is the highest power density of a dual-delta-doped AlGaAs/InGaAs/GaAs HEMT reported to date for low voltage (3 V) wireless applications.
5 mm high-power-density dual-delta-doped power HEMT's for 3 V L-band applications
(1996-05-01)
Lai, YL
;
Chang, EY
;
Chang, CY
;
Chen, TK
;
Liu, TH
A high-power-density dual-delta-doped AlGaAs/InGaAs/GaAs high electron mobility transistor (HEMT) for personal communication applications has been developed. A 5.0 mm gate-width device operating at a drain bias of 3.0 V gave an output power over 1 W, The 1 mu m gate-length HEMT exhibited a current density of 425 mA/mm at V-gs = 0.5 V, The maximum transconductance of the device was 270 mS/mm, The effective knee voltage was as low as 0.3 V, At the class AB operation, the HEMT demonstrated an output power density of 200 mW/mm, 64% power-added efficiency and 18.2 dB linear gain at 900 MHz, This is the highest power density of a dual-delta-doped AlGaAs/InGaAs/GaAs HEMT reported to date for low voltage (3 V) wireless applications.
Effects of metal-doped indium-tin-oxide buffer layers in organic light-emitting devices
(2006-06-01)
Chen, TH
;
Wu, TJ
;
Chen, JY
;
Liou, Y
;
顯示科技研究所
Organic light-emitting devices were fabricated by using different metal (V, Zr, Hf)-doped indium-tin-oxide (ITO) buffer layers on an ITO anode. The metal-doped ITO buffer layers were 15 nm thick with different metal concentrations. Both resistivity and work function of the ITO buffer layer were manipulated by these metal dopants. Different effects on the devices, such as reduced turn-on voltage, improved luminance, and enhanced current efficiency, were investigated. A low turn-on voltage was observed for devices with small work function and resistivity. The lowest turn-on voltage (3 V) was found on a device with a V-doped ITO buffer layer. The devices usually have a similar current density (J)-voltage (V) characteristics, but not the luminance-J or the current efficiency-J characteristics when the ITO buffer layers have the same work function. The devices with the Hf-doped ITO buffer layers show the best luminance performance among those considered. At 100 mA/cm(2), a luminance of 15,000 cd/m(2), and a current efficiency of 15 cd/A have been achieved. The balance between the carrier concentration and the energy barrier for the hole injection is possibly responsible for such performance.
HiPRIME: Hierarchical and passivity preserved interconnect macromodeling engine for RLKC power delivery
(2005-06-01)
Lee, YM
;
Cao, YH
;
Chen, TH
;
Wang, JML
;
Chen, CCP
This paper proposes a general hierarchical analysis methodology, HiPRIME, to efficiently analyze RLKC power delivery systems. After partitioning the circuits into blocks, we develop and apply the IEKS (Improved Extended Krylov Subspace) method to build the multiport Norton equivalent circuits which transform all the internal sources to Norton current sources at ports. Since there are no active elements inside the Norton circuits, passive or realizable model order reduction techniques such as PRIMA can be applied. The significant speed improvement, 700 times faster than Spice with less than 0.2% error and 7 times faster than a state-of-the-art solver, InductWise, is observed. To further reduce the top-level hierarchy runtime, we develop a second-level model reduction algorithm and prove its passivity.
Vanadium-doped indium tin oxide as hole-injection layer in organic light-emitting devices
(2005-12-12)
Chen, TH
;
Liou, Y
;
Wu, TJ
;
Chen, JY
;
顯示科技研究所
Organic light-emitting devices were fabricated by using vanadium-doped indium tin oxide (ITO) as the hole-injection layers between the hole transport layer, N,N-'-dia(1-napthl)-N,N-'-diphenyl benzidine and the ITO anode. The vanadium-doped ITO layer was 15-nm thick with three different vanadium concentrations (6, 10.5, and 12.5 mol %). Three different resistivities (10, 500, and 10 000 Omega cm) and work functions (5, 5.2, and 5.4 eV) were obtained. The device with 6 mol % V-doped ITO layer possessing the least resistivity (10 Omega cm) and work function (5 eV) has the lowest turn-on voltage (below 3 V), the lowest operating voltage (below 7 V), the highest luminance (1000 cd/m(2) below 7 V), and the highest power efficiency (>5 1m/W at 10 mA/cm(2)) among all. Such performance was attributed to the balance between the carrier concentration and the energy barrier for the hole injection.