• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
• /
• pp.1673-1676
• /
• 2007

We have investigated the degradation mechanism of hydrogenated amorphous silicon (a- Si:H) thin film transistors (TFTs) The threshold voltage of driving a-Si:H TFT is shifted severely by electrical bias due to a charge trapping and defect state creation. And the short channel TFTs exhibit less threshold voltage degradation than long channel TFTs. We propose the pixel circuits employing negative bias annealing scheme in order to suppression of threshold voltage shift of a-Si:H TFT.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
• /
• pp.63-63
• /
• 1999

The stability of hydrogenated amorphous silicon (a-Si:H) films under the light soaking are very important since the applications of a-Si:H films are solar cells, color sensors, photosensors, and thin film transistors(TFTs). We found the changes of the electric conductivity and the conductivity activation energy (Ea) of a-Si:H films by argon radical annealing. The deposition rate of a-Si:H films depends on the argon radical annealing time. The optical band gap and the hydrogen contents in the a-Si:H films are changes along the argon radical annealing time. We will discuss the microscopic processes of argon radical annealing in a-si:H films.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 하계학술대회 논문집 B
• /
• pp.1277-1279
• /
• 1993

As a highly information-oriented society developes, various kinds of amorphous semiconductor devices, such as solar cells, electrographic printers, image sensors, and flat-panel televisions, have been developed as man/machine interfaces. This paper proposed the laser CVD techniques to deposit hydrogenated amorphous silicon thin film on glass or dielectric substrate at low temperatures. Varying the deposition conditions, we examined optical and electrical charateristics of a-Si:H film deposited by Laser CVD.

• Current Photovoltaic Research
• /
• 제5권4호
• /
• pp.113-121
• /
• 2017

The researches on the silicon-based thin films are being actively carried out. The silicon-based thin films can be made as amorphous, microcrystalline and mixed phase and it is known that the optical bandgap can be controlled accordingly. They are suitable materials for the fabrication of single junction, tandem and triple junction solar cells. It can be used as a doping layer through the bonding of boron and phosphorus. The carbon and oxygen can bond with silicon to form a wide range of optical gap. Also, The optical gap of hydrogenated amorphous silicon germanium can be lower than that of silicon. By controlling the optical gaps, it is possible to fabricate multi-junction thin film silicon solar cells with high efficiencies which can be promising photovoltaic devices.

• 대한전자공학회논문지
• /
• 제26권3호
• /
• pp.130-136
• /
• 1989

보론이 도우핑된 수소화된 비정질 실리콘을 이용한 박막 트랜지스터를 플라즈마 CVD 방법으로 제작하여 트랜지스터의 특성 및 준안정성에 관한 연구를 수행하였다. 보론이 도우핑된 비정질 실리콘 ambipolar 트랜지스터를 열평형 온도 이상에서 급냉하면, active dopants가 증가하고 경계면 상태밀도가 감소하여 정공채널에 의한 드레인 전류가 증가하고 전자채널의 드레인 전류는 급냉 온도에 따라 증가하다 감소되는 현상을 측정하였다. 이런 급냉 효과는 실리콘내에 있는 수소의 운동과 밀접한 관계가 있고 active dopants, 댕글링 본드 및 경계면 상태밀도의 변화로 해석된다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1701-1703
• /
• 2006

Here we describe a novel driving scheme in the form of negative AC bias stress (NAC) to compensate shift in the threshold voltage for hydrogenated amorphous silicon (${\alpha}$-Si:H) thin film transistor (TFT) for AMOLED applications. This scheme preserves the threshold voltage shift of ${\alpha}$-Si:H TFT for infinitely long duration of time(>30,000 hours) and thereby overall performance, without using any additional TFTs for compensation. We briefly describe about the possible driving schemes in order to implement for real time AMOLED applications. We attribute most of the results based on concept of plugging holes and electrons across the interface of the gate insulator in a controlled manner.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.426.1-426.1
• /
• 2016

We report high work function Aluminum doped zinc oxide (AZO) films as insertion layer as a function of O2 flow rate between transparent conducting oxides (TCO) and hydrogenated amorphous silicon oxide (a-SiOx:H) layer to improve open circuit voltage (Voc) and fill factor (FF) for high efficiency thin film solar cell. However, amorphous silicon (a-Si:H) solar cells exhibit poor fill factors due to a Schottky barrier like impedance at the interface between a-SiOx:H windows and TCO. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiOx:H. In this study, we report on the silicon thin film solar cell by using as insertion layer of O2 reactive AZO films between TCO and p-type a-SiOx:H. Significant efficiency enhancement was demonstrated by using high work-function layers (4.95 eV at O2=2 sccm) for engineering the work function at the key interfaces to raise FF as well as Voc. Therefore, we can be obtained the conversion efficiency of 7 % at 13mA/cm2 of the current density (Jsc) and 63.35 % of FF.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.80-82
• /
• 2009

The dependence of the efficiency characteristics of hydrogenated amorphous silicon single junction solar cells on the various intrinsic layer thickness has been investigate in the glass/$SnO_2$:F/p,i,n a-Si:H/Al type of amorphous silicon solar cells by cluster PECVD system. The open circuit voltage, short circuit current, fill factor and conversion efficiency have been measured under AM 1.5 condition. The result of the cell performance was improved about 8.2% due to an increase in the short circuit current.

• Journal of Advanced Marine Engineering and Technology
• /
• 제41권2호
• /
• pp.146-149
• /
• 2017

Si clusters generated during the plasma chemical vapor deposition (CVD) process have a great influence on the quality of the fabricated films. In particular, in hydrogenated amorphous silicon thin films (a-Si:H) used for thin film solar cells, Si clusters are mainly responsible for light-induced degradation. In this study, we investigated the amount of clusters incorporated into thin films using a quartz crystal microbalance (QCM) and specially designed cluster eliminating filters, and investigated the effect of the DC grid mesh in preventing cluster incorporation. Experimental results showed that as the applied voltage of the grid mesh, which is placed between the electrode and the QCM, decreased, the number of clusters incorporated into the film decreased. This is due to the electrostatic force from the grid mesh bias, and this method is expected to contribute to the fabrication of high-quality thin films by preventing Si cluster incorporation.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.172-175
• /
• 2009

n-type crystalline silicon wafers were passivated with intrinsic a-Si:H thin films on both sides using HWCVD. Minority carrier lifetime measurement was used to verify interface passivation properties between a-Si:H thin film and crystalline Si wafer. Thin film interface characteristics were investigated depending on $H_2/SiH_4$ ratio and hot wire deposition temperature. Vacuum annealing were processed after deposition a-Si:H thin films on both sides to investigate thermal effects from post process steps. We noticed the effect of interface passivation properties according to $H_2/SiH_4$ ratio and hot wire deposition temperature, and we had maximum point of minority carrier lifetime at H2/SiH4 10 ratio and $1600^{\circ}C$ wire temperature.