• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.338-341
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• 2002

A new small size Lateral Trench Electrode Insulated Gate Bipolar Transistor (LTEIGBT) is proposed and fabricated to improve the characteristics of device. The entire electrode of LTEIGBT is placed to trench type electrode. The LTEIGBT is designed so that the width of device is 19$\mu\textrm{m}$. The latch-up current density of the proposed LTEIGBT is improved by 10 and 2 times with those of the conventional LIGET and LTIGBT The forward blocking voltage of the LTEIGBT is 130V. At the same size, those of conventional LIGBT and LTIGBT are 60V and 100V, respectively. Because that the electrodes of the proposed device is formed of trench type, the electric field in the device are crowded to trench oxide. We fabricated He proposed LTEIGBT after the device and process simulation was finished. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT and the conventional LIGBT are 80mA and 70mA, respectively, at the same breakdown voltage of 150V,

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.9
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• pp.758-763
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• 2002

A new small size Lateral Trench Electrode Insulated Gate Bipolar Transistor (LTEIGBT) is proposed and fabricated to improve the characteristics of device. The entire electrode of LTEIGBT is placed to trench type electrode. The LTEIGBT is designed so that the width of device is 19w. The latch-up current density of the proposed LTEIGBT is improved by 10 and 2 times with those of the conventional LIGBT and LTIGBT. The forward blocking voltage of the LTEIGBT is 130V. At the same size, those of conventional LIGBT and TIGBT are 60V and 100V, respectively. Because the electrodes of the proposed device is formed of trench type, the electric field in the device are crowded to trench oxide. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT and the conventional LIGBT are 80mA and 70mA, respectively, at the same breakdown voltage of 150V.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.34-39
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• 2006

In high-voltage devices such as thyristor, beveling is mostly used junction termination method to reduce the surface electric field far below the bulk electric field and to expand the depletion region thus that breakdown occurs in the bulk of the device rather than at the surface. However, coating material used to protect the surface of the device contain so many charges which affect the electrical characteristics of the device. And device reliability is also affected by this charge. Therefore, it is needed to analyze the effect of surface charge on electrical characteristics of the device. In this paper, we analyzed the breakdown voltage and leakage current characteristics of the thyristor as a function of the amount of surface charge density. Two dimensional process simulator ATHENA and two-dimensional device simulator ATLAS is used to analyze the surface charge effects.

• Transactions on Electrical and Electronic Materials
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• v.2 no.1
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• pp.32-38
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• 2001

A new small sized Lateral Trench electrode Insulated Gate Bipolar Transistor(LTEIGBT) was proposed to improve the characteristics of conventional Lateral IGBT (LIGBT) and Lateral Trench gate IGBT (LTIGBT). The entire electrode of LTEIGBT was replace with trench-type electrode. The LTEIGBT was designed so that the width of device was no more than 19 ㎛. The Latch-up current densities of LIGBT, LTIGBT and the proposed LTEIGBT were 120A/㎠, 540A/㎠, and 1230A/㎠, respectively. The enhanced latch-up capability of the LTEIGBT was obtained through holes in the current directly reaching the cathode via the p+ cathode layer underneath n+ cathode layer. The forward blocking voltage of the LTEIGBT is 130V. Conventional LIGBT and LTIGBT of the same size were no more than 60V and 100V, respectively. Because the the proposed device was constructed of trench-type electrodes, the electric field moved toward trench-oxide layer, and punch through breakdown of LTEIGBT is occurred, lately.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.83-88
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• 2004

BAlq was fabricated as for hole blocking layer in the OLED devices to investigate its electrical and optical characteristics. Device structure was ITO/$\alpha$ -NPD/EML/BAlq/Alq3/Al:Li using TYG-201, DPVBi (4, 4 - Bis (2, 2 - diphenylethen-1 - yls) - Biphenyl), Alq and DCJTB (4-(dicyanomethylene)-2- (1-propyls)6-methy 4H-pyrans) as green emitting material, blue emitting material, host material for red emission and red emitting guest material respectively. The OLED device showed optimum working voltage and electron density at 600 cd/$m^2$ when thickness of BAlq is 25$\AA$ for RGB OLED devices while their efficiencies are better at 50$\AA$ of BAlq. Red and blue color OLEDs also fabricated using 30$\AA$ thickness of BAlq and compared with those without BAlq layer. BAlq was more effective in electrical properties such as working voltage, current density and efficiency of red OLED than blue and green ones. This study describes that 30$\AA$ is optimum thickness of BAlq for best performance of full color OLED devices when using BAlq as a hole blocking material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04b
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• pp.20-21
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• 2008

Photovoltaic effects in organic solar cell were studied in a cell configuration of ITO/PEDOT:PSS/CuPd(20nm)/$C_{60}$(40nm)/BCP/Al(150nm) at room temperature. Here, the BCP layer works as an exciton blocking layer. The exciton blocking layer must transport electrons from the acceptor layer to the metal cathode with minimal increase in the total cell series resistance and should absorb damage during cathode deposition. Therefore, a proper thickness of the exciton blocking layer is required for an optimized photovoltaic cell. Several thicknesses of BCP were made between $C_{60}$ and Al. And we obtained characteristic parameters such as short-circuit current, open-circuit voltage, and power conversion efficiency of the device under the illumination of AM 1.5.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.14-15
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• 2009

Insulated Gate Bipolar Transistor(IGBTs) are widely used in power device industry. However, to improve the breakdown voltage, IGBTs are suffered from increasing on-state voltage drop due to structural design. In this paper, the new structure is proposed to solve this problem. The proposed structure has double p-floating layer inserted in n-drift layer. The p-floating layers improve the breakdown voltage compared to conventional IGBT without change of other electrical characteristics such as on-state voltage drop and threshold voltage. this is because the p-floating layers expand electric field distribution at blocking state. A electrical characteristic of proposed structure is analyzed by using simulators such as TSUPREM and MEDICI. As a result, on-state voltage drop and threshold voltage are same to a conventional TIGBT, but breakdown voltage is improved to 16%.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.160-161
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• 2003

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.598-602
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• 2002

This paper presents the 3-phase hybrid series active power filter with dynamic voltage restorer(DVR) which serve as an energy buffer and current harmonics blocking resistor connected to sensitive loads, such as, to compensate voltage dips and current harmonics in power distribution system. The DVR is to inject a dynamically controlled voltage generated by a forced commutated converter in series to the bus voltage by means of a booster transformer. The momentary amplitudes of the three injected phase voltages are controlled such as to eliminate any detrimental effects of a bus fault to the load voltage. The proposed system is able to simultaneously compensate current harmonics, voltage fluctuating and voltage unbalance in power distribution systems. The reference phase angle detected by synchronized with the positive sequence component of the unbalanced source by using symmetrical component transformation. The effectiveness of proposed system is verified by the computer simulation.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.151-154
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• 2001

This paper propose a new active common-mode voltage damper circuit that is capable of suppressing a common-mode voltage produced in the PWM VSI. The new active common mode voltage damper is consisted of a half-bridge inverter and a common mode transformer with a blocking capacitor. Principle of the active common mode damper is as follow; by applying the compensation voltage which has the same amplitude and opposite polarity to the PWM inverter system. So, common mode voltage and high frequency leakage current can be reduced. Simulated and experimental results show that common-mode voltage damper makes contributions to reducing a high frequency leakage current and common-mode voltage.