Browsing by Author "Hong, JW"

Now showing 1 - 7 of 7

Characteristics of SiC-based thin-film LED fabricated using plasma-enhanced CVD system with stainless steel mesh
(1999-07-22)
Chen, YA
;
Hsu, ML
;
Laih, LH
;
Hong, JW
;
Chang, CY
A conventional plasma-enhanced chemical vapour deposition (PECVD) system with a stainless steel mesh attached to a cathode was used to fabricate an SiC-based thin-mm light-emitting diode (TFLED) at a low temperature (similar to 180 degrees C). The obtained TFLED had a brightness (B) of 1060cd/m(2) at an injection current density (J) of 600mA/cm(2) and a threshold voltage (V-th) of 12.6V, which were much better than those of 330cd/m(2) and 18.5V for an amorphous SiC-based TFLED fabricated by the same PECVD system without a stainless steel mesh.
Double graded-gap hydrogenated amorphous silicon carbide thin-film light-emitting diode with composition-graded N layer and carbon-increasing P layer
(1996-02-01)
Chen, YA
;
Chen, JK
;
Tsay, WC
;
Laih, LH
;
Hong, JW
An hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diode (TFLED), in which a composition-graded n layer and carbon-increasing p layer respectively replace the constant optical-gap p-a-SiC:H layer and n-a-SiC:H layer employed in the previously reported double graded-gap (DG) TFLED and which contains dopant-graded p-i and i-n junctions, was successfully fabricated tu improve the electroluminescence (EL) of TFLED. This device had a brightness of 400 cd/m(2) at an injection current density of 600 mA/cm(2) and its EL threshold voltage (V-th) was only 9.0 V. The device EL spectrum showed a peak at 586 nm wavelength and emitted yellowish-orange light. The proposed TFLED had good stability of EL intensity and the EL spectrum during normal operation. The optimum conditions of rapid thermal annealing (RTA), which improved the ohmic contact between the amorphous layer and external electrode of the device, were 5 min at 300 degrees C in a 250 Torr H-2 ambient.
Electrical and luminescent characteristics of alpha-SiC:H p-i-n thin-film LED's with graded-gap junctions
(1997-04-01)
Jen, TS
;
Shin, NF
;
Laih, LH
;
Chen, YA
;
Hong, JW
A-SiC:H p-i-n thin-film LED's (TFLED's) containing a single graded-gap p-i-n junction (SG) or double graded-gap p-i-n and i-n junctions (DG) have been postulated and fabricated successfully on indium-tin-oxide (ITO)-coated glass substrates, with a plasma-enhanced chemical vapor deposition (PECVD) system, Some important characteristics and related physics of these two types of TFLED's are presented and discussed, At an injection current density (J) of 600 mA/cm(2), the brightness (B) of the SG and DG TFLED's obtained were 30 and 207 cd/m(2), respectively, This significant improvement of brightness, as compared to those of the previously reported TFLED's with a highest brightness of 20 cd/m(2), could be ascribed to the reduced interface states with the graded-gap junctions, lower contact resistance between ITO and p-layer due to a plasma treatment of ITO prior to p-layer deposition, post metallization annealing of thermally evaporated Al on n-layer, and higher optical gaps (E(opt)'s) of the doped layers employed, The slopes of the nearly linear B-J relationships show the diode factor very close to unity for the fabricated SG and DG TFLED's, This implies that the electroluminescence (EL) mechanism of these TFLED's might be a tail-to-tail-state recombination, In addition, the conduction currents of these TFLED's are almost temperature dependent, and that of the DG TFLED might consist of an ohmic current and a space-charge-limited current (SCLC) within the lower and higher applied-bias regions, respectively.
Optoelectronic characteristics of a-SiC : H-based pin thin film LEDs having a thin Mo buffer layer in contact with p-type a-Si : H
(1998-07-09)
Chen, YA
;
Wu, YH
;
Tsay, WC
;
Laih, LH
;
Hong, JW
To improve the electroluminescence (EL) properties of the nSiC:H-based pin thin film light-emitting diodes (TFLEDs) with the promotion of hole injection efficiency, a thin Mo metal film was used as a buffer layer to prevent reactions between the ITO (indium-tin-oxide) electrode and the p(+)-a-Si:H layer. With the formation of semi-transparent Mo silicide after annealing, a lower EL threshold voltage and a significantly higher brightness for a finished TFLED were achieved. The brightness of the obtained device was 1300cd/m(2) at an injection current density of 600mA/cm(2), and its EL threshold voltage was 14V.
Optoelectronic characteristics of alpha-SiC:H-based P-I-N thin-film light-emitting diodes with low-resistance and high-reflectance N+-alpha-SiCGe:H layer
(1997-09-01)
Chen, YA
;
Chiou, CF
;
Tsay, WC
;
Laih, LH
;
Hong, JW
The graded-gap a-SiC:II-based p-i-n thin-film light-emitting diodes (TFLED's) with an additional low-resistance and high-reflectance n(+)-a-SiCGe:H layer mere proposed and fabricated on indium-tin-oxide (ITO)-coated glass substrate in this paper. For a finished TFLED, a brightness of 720 cd/m(2) could be obtained at an injection current density of 600 mA/cm(2), and its EL (electroluminescence) threshold voltage was lowered to 8.6 V. in addition, the effects of reflectance and resistance of a-SiCGe:H film an the performance of TFLED were discussed, The optimum rapid thermal annealing (RTA) conditions for fabrication of TFLED after metallization were also studied and employed to improve the optoelectronic characteristics of TFLED.
Optoelectronic characteristics of alpha-SiC:H-based P-I-N thin-film light-emitting diodes with low-resistance and high-reflectance N+-alpha-SiCGe:H layer
(1997-09-01)
Chen, YA
;
Chiou, CF
;
Tsay, WC
;
Laih, LH
;
Hong, JW
The graded-gap a-SiC:II-based p-i-n thin-film light-emitting diodes (TFLED's) with an additional low-resistance and high-reflectance n(+)-a-SiCGe:H layer mere proposed and fabricated on indium-tin-oxide (ITO)-coated glass substrate in this paper. For a finished TFLED, a brightness of 720 cd/m(2) could be obtained at an injection current density of 600 mA/cm(2), and its EL (electroluminescence) threshold voltage was lowered to 8.6 V. in addition, the effects of reflectance and resistance of a-SiCGe:H film an the performance of TFLED were discussed, The optimum rapid thermal annealing (RTA) conditions for fabrication of TFLED after metallization were also studied and employed to improve the optoelectronic characteristics of TFLED.
Porous silicon light-emitting diode with tunable color
(1997-05-01)
Chen, YA
;
Chen, BF
;
Tsay, WC
;
Laih, LH
;
Chang, MN
We successfully combined porous silicon and amorphous silicon together to fabricate a light-emitting diode, whose emitting color was tunable with different applied voltage. When the applied voltage increased from 30 to 90 V, the emitting color of the device could change from red to blue. (C) 1997 Elsevier Science Ltd.