• Journal of the Semiconductor & Display Technology
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• v.11 no.4
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• pp.19-23
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• 2012

We report microbolometer characteristic with n-type and p-type amorphous silicon thin film. The n-type and p-type amorphous silicon thin films were made by PECVD. The electrical properties of n-type and p-type a-Si:H thin films were investigated as a function of doping gas flow rate. The doping gas used $B_2H_6/Ar$ (1:9) and $PH_3/Ar$ (1:9). In general, the conductivity of doping a-Si:H thin films increased as doping gas increase but the conductivity of a-Si:H thin films decreased as the doping gas increase because doping gas concentration increase led to dilution gas (Ar) increase as the same time. We fabricated an amorphous silicon microbolometer using surface micromachining technology. The fabricated microbolometer had a negative TCR of 2.3%. The p-type microbolometer had responsivity of $5{\times}10^4V/W$ and high detectivity of $3{\times}10^8cm(Hz)^{1/2}/W$. The p-type microbolometer had more detectivity than n-type for less noise value.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1001-1004
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• 2008

An advanced backplane circuit technology for AMOLED using amorphous silicon TFTs with commercial level reliability, uniformity and lifetime was recently integrated into a prototype device. Differential aging of T98>100 hrs at 200 cd/m2 brightness and >10,000hrs lifetime is demonstrated. A 2.2" QVGA ($240{\times}320$) prototype has been developed and shown having the above-mentioned high performance.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.346.2-346.2
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• 2016

The rear side contact recombination in the crystalline silicon solar cell could be reduced by back surface field. We formed polycrystalline silicon as a back surface field through crystallization of amorphous silicon. A thin silicon oxide applied to the passivation layer. We used quasi-steady-state photoconductance measurement to analyze electrical properties with various annealing condition. And, blister formed on surface of wafer during the annealing process. We observed the blister after varied annealing process with wafer of various surface. Shape and density of blister is influenced by various annealing temperature and process time. As the annealing temperature became higher, the average diameter of blister is decreased and total number of blister is increased. The sample with the $600^{\circ}C$ annealing temperature and 1 min annealing time exhibited the highest implied open circuit voltage and lifetime. We predicted that the various shape and density of blister affects the lifetime and implied open circuit voltage.

• Electrical & Electronic Materials
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• v.7 no.2
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• pp.94-99
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• 1994

The purpose of this work is to investigate the interface characteristics of hydrogenated amorphous silicon thin films prepared by PECVD and photo-induced CVD and to examine the annealing effects of ultraviolet irradiation on hydrogenated amorphous silicon thin films which were degraded by visible light illumination. The interface layer thickness of films deposited by photo-induced CVD was about 600-900.angs. while that by PECVD was about 1000-1300.angs.. These results can show that the quality of interface layer in photo induced CVD film is better than that in PECVD sample. The electrical properties are improved by ultraviolet irradiation on visible light soaked a-Si:H films using photo-CVD light sources, probably due to the fact that UV generates phonons in a-Si:H films and anneal the meta stable defects.

• ETRI Journal
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• v.28 no.1
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• pp.45-50
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• 2006

An RC oscillator using amorphous silicon thin film transistors was developed. The oscillation frequency and its dependence on resistance and bias voltage were studied. The frequency was controlled by adjusting the feedback resistance of the oscillator. The highest measured frequency of the oscillator was around 140 kHz, which is acceptable for low-end radio frequency identification (RFID). Since a low-end RFID circuit needs low cost and a simple process, an amorphous silicon oscillator is suitable.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.973-979
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• 1995

The input equivalent noise charge (ENC) of hydrogenated amorphous silicon radiation detector diodes was measured and analyzed. The noise sources of amorphous silicon diodes were analyzed into three sources; shot noise, flicker noise and thermal noise from the contact resistance. By comparing the measured ENC with the calculated signal charge in uniform generation case, the signal-to-noise ratio (S/N) for the sample diodes is estimated as a function of the detector bias and the shaping time of Gaussian pulse shaper. The maximum S/N occurred at the bias level just above the full depletion voltage for shaping time of 2∼3 ${\mu}$sec. The developed method is useful in optimum design or amorphous silicon p-i-n diodes for charged particulate radiation spectroscopy.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.3
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• pp.453-458
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• 1987

Amorphous silicon thin-film transtors (TFT's) have been designed and fabricated on glass substrates. The hydrogenated amorphous silicon (a-Si:H) thin-film has been deposited by decomposing silane(SiH4) in hydorgen ambient by rf glow discharge method. Amorphous silicon nitride(a-Si:H) has been chosen as the gate dielectric material. It has been prepared by decomposing the mixed gas of silane(SiH4) and ammonia(NH3). The electrical properties and performance characteristics of the thin-film transistrs have been measured and compared with the requirements for the switching elements in liquid crystal flat panel display. The results show that liquid crystal flat panel displays can be fabricated using the thin-film transistors described in this paper.

• Analytical Science and Technology
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• v.24 no.2
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• pp.105-112
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• 2011

Syntheses and property analysis of hydropolysilanes were studied. Those hydropolysilanes can be utilized as precursors for amorphous silicon and polycrystallline silicon for the purpose of the solar cell and the thin film transister for the next generation's semiconductors. Most important characteristics of this study are to find optimized conditions for the synthesis and property analysis of soluble hydropolysilanes. Also the possibility of pyrolytic conversion to amorphous and polycrystalline silicon was investigated.

• Current Photovoltaic Research
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• v.5 no.4
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• pp.113-121
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• 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.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1181-1183
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• 1995

In this study, we observed the surface morphology of amorphous silicon annealed at $700{\sim}1000^{\circ}C$ for recrystallization. In case of $700{\sim}800^{\circ}C$ annealing, deposited amorphous silicon have the saturated XRD intensity and decreased surface roughness after annealing for 3 hours. It is thought that surface roughness of amorphous silicon increases because of contributions caused by atomic rearrangement of surface, for instance, surface stress etc., in the course of recrystallinzation and decrease because of the relaxation of stress by annealing in reaching completion of recrystallization. In case of $1000^{\circ}C$ annealing, the effect of grain size on deposited silicon is more effective than that of surface roughness. These results show that small grain silicon has the stronger dependence on surface roughness than large grain one.