Browsing by Author "HONG, JW"

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A HYDROGENATED AMORPHOUS SI/SIC HETEROJUNCTION PHOTOTRANSISTOR
(1989-10-01)
HONG, JW
;
CHEN, YW
;
CHANG, KC
;
FANG, YK
;
CHANG, CY
AMORPHOUS SI/SIC PHOTOTRANSISTORS AND AVALANCHE PHOTODIODES
(1991-06-01)
CHANG, CY
;
HONG, JW
;
FANG, YK
;
交大名義發表
;
National Chiao Tung University
The device structures, operation principles, optoelectronic characteristics, performance comparisons, and possible applications for various a-Si:H/a-SiC:H phototransistors and avalanche photodiodes are reviewed. Although these devices are made of amorphous semiconductors, its majority-carrier transport properties can tactfully avoid gap-state and defect related minority-carrier transport problems, and obtain good performances. Also, each of these devices has the distinct advantage of meeting the requirements of different practical applications. The unique and distinct advantages of these a-Si:H/a-SiC:H devices are first, a variety of peak response wavelengths are achievable by changing the composition or the well-to-barrier widths of the superlattice, secondly, a large-area-detector image sensor can be made on a glass substrate; and thirdly, the low-temperature of the amorphous films (approximately 250-degrees-C) possesses a very abrupt composition change and a doping profile, which are impossible in the single-crystalline semiconductors.
AMORPHOUS-SILICON SILICON-CARBIDE SUPERLATTICE AVALANCHE PHOTODIODES
(1988-08-01)
JWO, SC
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WU, MT
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FANG, YK
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CHEN, YW
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HONG, JW
EFFECTS OF N2O-PLASMA TREATMENT OF A-SIOXNY/A-SINX GATE INSULATORS ON ELECTRICAL STABILITY OF A-SIH THIN-FILM TRANSISTORS
(1994-07-15)
JEN, TS
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LEU, ST
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CHOU, TC
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HONG, JW
;
CHANG, CY
N2O-plasma was used to treat the as-deposited a-SiO(x)N(y)/a-SiN(x) gate insulators of inverted-staggered a-Si:H thin-film transistors (TFTs), and its effects on electrical properties of TFTs were investigated. The TFTs with N2O-plasma-treated gate insulators tended to have a smaller threshold voltage (V(th)), V(th) Shift and hysteresis width (W(FB)) of the forward and backward transfer characteristics. In addition, the results of a bias-temperature stress (BTS) experiment showed that the N2O-Plasma-treated devices had a smaller decay of drain current with time. These phenomena demonstrated that the N2O-PlasMa treatment could be used to improve the electrical stability of a-Si:H TFTs.
ELECTROLUMINESCENCE CHARACTERISTICS AND CURRENT-CONDUCTION MECHANISM OF A SI-C-H-P-I-N THIN-FILM LIGHT-EMITTING-DIODES WITH BARRIER LAYER INSERTED AT P-I INTERFACE
(1994-10-01)
JEN, TS
;
PAN, JW
;
SHIN, NF
;
HONG, JW
;
CHANG, CY
In order to improve the electroluminescence (EL) characteristics of the hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diode (TFLED), a barrier layer (BL) was inserted at its p-i interface to enhance the hole injection efficiency under forward-bias operation. The a-SiC:H TFLED's with various optical gaps of BL had been fabricated and characterized. In addition, a composition-graded n+-layer was used to reduce its series and contact resistances to the Al electrode and hence the EL threshold voltage (V(th)) of an a-SiC:H BL TFLED. The highest obtainable brightness of an a-SiC:H BL TFLED was 342 cd/m2 at an injection current density of 600 mA/cm2 and the lowest EL V(th) achievable was 6.0 V. The current-conduction mechanism of an a-SiC:H BL TFLED had also been investigated. Within the lower applied-bias region, it showed an ohmic current, while within the higher applied-bias region, a space-charge-limited current (SCLC) was observed.
ELECTROLUMINESCENCE CHARACTERISTICS AND CURRENT-CONDUCTION MECHANISM OF A SI-C-H-P-I-N THIN-FILM LIGHT-EMITTING-DIODES WITH BARRIER LAYER INSERTED AT P-I INTERFACE
(1994-10-01)
JEN, TS
;
PAN, JW
;
SHIN, NF
;
HONG, JW
;
CHANG, CY
In order to improve the electroluminescence (EL) characteristics of the hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diode (TFLED), a barrier layer (BL) was inserted at its p-i interface to enhance the hole injection efficiency under forward-bias operation. The a-SiC:H TFLED's with various optical gaps of BL had been fabricated and characterized. In addition, a composition-graded n+-layer was used to reduce its series and contact resistances to the Al electrode and hence the EL threshold voltage (V(th)) of an a-SiC:H BL TFLED. The highest obtainable brightness of an a-SiC:H BL TFLED was 342 cd/m2 at an injection current density of 600 mA/cm2 and the lowest EL V(th) achievable was 6.0 V. The current-conduction mechanism of an a-SiC:H BL TFLED had also been investigated. Within the lower applied-bias region, it showed an ohmic current, while within the higher applied-bias region, a space-charge-limited current (SCLC) was observed.
ELECTROLUMINESCENCE OF A-SIC-H P-I-N THIN-FILM LIGHT-EMITTING-DIODES WITH QUANTUM-WELL-INJECTION STRUCTURES
(1994-09-01)
JEN, TS
;
SHIN, NF
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TSAY, WC
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CHEN, JY
;
NING, SL
In order to improve the electroluminescence (EL) characteristics of hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diodes (TFLEDs), the quantum-well-injection (QWI) structures have been incorporated into their intrinsic (i-) layer. Two types of TFLED were fabricated to study the effect of the incorporated QWI structures on their EL characteristics: the device I contains a step-gap QWI structure of barrier (15 angstrom)/well (45 angstrom)/barrier (15 angstrom) inserted at both the p-i and i-n interfaces, and the device Il has only one graded-gap QWI structure of barrier (10 angstrom)/well (10 angstrom)/barrier (10 angstrom) inserted at the p-i interface. The obtained brightness of device I was about 10 cd/m2 at an injection current density of 1 A/cm2. The emission light of device I was yellow-like as detected by human eyes. Whereas, for device II, the brightness was about 256 cd/m2 at 800 mA/cm2 and an orange light emission was observed.
GRADED-GAP A-SIC-H P-I-N THIN-FILM LIGHT-EMITTING-DIODES
(1992-07-01)
HONG, JW
;
SHIN, NF
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JEN, TS
;
NING, SL
;
CHANG, CY
In order to improve the performance of hydrogenated amorphous-silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diodes (TFLED's), a p-i-n TFLED with a graded p-i junction has been proposed and fabricated. The electroluminescence (EL) intensity of the proposed TFLED was more than 100 times higher than that of the basic p-i-n TFLED and about 35 times lower than that of the conventional green LED, at the same injection current density. This significant improvement was attributed to the better interface property and enhancement of hole injection efficiency by using the graded-gap p-i junction.
HYDROGENATED AMORPHOUS SI/SIC SUPERLATTICE PHOTOTRANSISTORS
(1991-02-01)
WU, MT
;
FANG, YK
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HONG, JW
;
CHANG, CY
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電控工程研究所
In order to improve the performance of the a-Si:H phototransistor (PT) and the a-Si:H/a-SiC:H heterojunction phototransistor (HPT), the a-Si:H/a-SiC:H superlattice (SL) was used for the collector regions of these two devices individually. The resulting superlattice phototransistor (SLPT) and superlatice heterojunction phototransistor (SHPT) were successfully fabricated. Due to the avalanche multiplication in the interpolated a-Si:H/a-SiC:H SL region, the optoelectronic characteristics of the SLPT and the SHPT are considerably better than those of PT and HPT. The SLPT has high photocurrent response and an optical gain as high as 287, when V(CE) = 14 V, I(c) = 0.74 mA, and P(in) (incident power) = 5-mu-W emitted from He-Ne laser. This is the highest optical gain obtainable for various amorphous phototransistors yet reported. The typical shapes of the photo I-V curves for SHPT are much like those of the crystalline-Si (c-Si) phototransistor. This indicates the SHPT is suitable for analog circuits in optoelectronic applications. The SHPT has a maximum optical gain of 78, when V(CE) = 30 V, I(c) = 0.208 mA, and P(in) = 5-mu-W. The response time for SHPT and SLPT are repectively 4.1 +/- 0.1-mu-s and 6.2 +/- 0.1-mu-s at a load resistance R(L) = 1 k-omega.
HYDROGENATED AMORPHOUS SILICON-CARBIDE THIN-FILM LIGHT-EMITTING DIODE WITH QUANTUM-WELL-INJECTION STRUCTURE
(1993-04-15)
JEN, TS
;
CHEN, JY
;
SHIN, NF
;
HONG, JW
;
CHANG, CY
To improve the electroluminescence (EL) intensity of the hydrogenated amorphous silicon carbide (a-SiC:H) pin thin-film light-emitting diode (TFLED), a quantum-well-injection (QWI) structure has been incorporated into the i-layer of an a-SiC:H pin TFLED at the p-i interface. The obtained brightness of this QWI TFLED is 256 cd/m2 at an injection current density of 800 mA/cm2, which is about three orders of magnitude higher than the brightness of an a-SiC:H pin TFLED. Also, a comparatively lower EL threshold voltage of 6 V was observed for this a-SiC:H QWI TFLED.
HYDROGENATED AMORPHOUS-SILICON CARBIDE DOUBLE GRADED-GAP P-I-N THIN-FILM LIGHT-EMITTING-DIODES
(1993-09-01)
SHIN, NF
;
CHEN, JY
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JEN, TS
;
HONG, JW
;
CHANG, CY
Hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diodes (TFLED's) with graded p+-i and i-n+ junctions have been proposed and fabricated successfully on an indium-tin-oxide (ITO)-coated glass. An obtained orange TFLED reveals a brightness of 207 cd/m2 at an injection current density of 600 mA/cm2, which is the brightest one ever reported for a-SiC:H TFLED's at the same injection current density. This significant increase of brightness could be ascribed to the combined effect of reduced interface states by using the graded-gap junctions, lower contact resistance due to post-metallization annealing, and higher optical gaps of the doped layers.
HYDROGENATED AMORPHOUS-SILICON CARBIDE P-I-N THIN-FILM LIGHT-EMITTING-DIODES WITH BARRIER LAYERS INSERTED AT P-I INTERFACE
(1994-01-01)
JEN, TS
;
PAN, JW
;
SHIN, NF
;
TSAY, WC
;
HONG, JW
To improve the electroluminescence (EL) intensity of the hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diode (TFLED), a barrier-layer (BL) structure had been inserted at its p-i interface and used to enhance the hole injection efficiency of TFLED under forward-bias operation. Two TFLEDs with different BL structures were studied. The device I had a 25 Angstrom A i-type single-barrier structure and the device II had an i-type double-barrier structure of barrier (10 Angstrom A)/well(10 Angstrom A)/barrier(10 Angstrom A). The obtainable brightness of device I was 342 cd/m(2) at an injection current density of 600 mA/cm(2). On the other hand, the device II had a brightness of 256 cd/ m(2) at 800 mA/cm(2). These brightnesses were about 3 orders of magnitude higher than that of a basic a-SiC:H p-i-n TFLED.
INVESTIGATION OF NEW NARROW-BANDWIDTH A-SI-H PHOTODETECTOR
(1994-06-01)
SHIN, NF
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HONG, JW
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WU, YF
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JEN, TS
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CHANG, CY
A narrow-bandwidth hydrogenated amorphous silicon (a-Si : H) photodetector with a basic structure of Al/n+-i-p+-i-n-i-p-i-n+/ITO/glass has been investigated. The spectral response of this new photodetector was found to be affected by the absorption coefficient of a-Si:H material, surface recombination current, device layer thicknesses, and applied bias. The spectral response of this device reveals a measured minimum FWHM of 58 nm at zero volt bias. The peak wavelength in the visible spectrum can be shifted from 400 nm (purple) to 550 nm (green) by decreasing the bias voltage from 5 to 0 V. The optoelectronic characteristics of this photodetector fit theoretically using suitable quantitative estimates.
OPTICAL AND NOISE CHARACTERISTICS OF AMORPHOUS SI/SIC SUPERLATTICE REACH-THROUGH AVALANCHE PHOTODIODES
(1990-08-01)
HONG, JW
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LAIH, WL
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CHEN, YW
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FANG, YK
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CHANG, CY
THE HYDROGENATED AMORPHOUS-SILICON REACH-THROUGH AVALANCHE PHOTODIODES (A-SI-H RAPDS)
(1990-02-01)
HONG, JW
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CHEN, YW
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LAIH, WL
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FANG, YK
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CHANG, CY