• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.25-27
• /
• 2007

$Eu^{2+}$-doped $Ca_2Si_5N_8$ was grown on Si(100) substrate using metal-organic deposition (MOD) method and post-annealed at $900^{\circ}C$ in various atmosphere. Luminescence properties of these thin films were investigated with variations of $Eu^{2+}$-doped concentrations and annealing atmosphere. Thin film was formed with clean surface and uniform thickness of about 72 nm. From the measurements of luminescence properties of thin films, film must be post-annealed in nitrogen or mixture of nitrogen and hydrogen atmosphere to emit a sufficient light. For $Ca_{1.5}Eu_{0.5}Si_5N_8$ thin film annealed at $900^{\circ}C$ in nitrogen atmosphere, excitation band from 380 to 420 nm was detected with the maximum intensity at 404 nm and two broad emission bands from 530 to 630 nm were observed. These broad excitation and emission bands must be attributed to the nitrogen incorporations into the films. From the results, $Ca_{2-x}Eu_xSi_5N_8$ thin film has probability for next generation thin film lighting applications such as light emitting diode (LED) or electro-luminescence (EL).

• 한국전기전자재료학회논문지
• /
• 제14권3호
• /
• pp.234-240
• /
• 2001

Using RF magnetron sputtering, amorphous carbon(a-C) thin films as electron filed emitter were fabricated. these a-C thin films were deposited on Si(001) substrate at several temperatures. The field electron emission property of these a-C thin films was estimated by a diode technique. As the result, we observed that the field emission properties of the films were changed singnificantly with the substrate temperature and structural features of a-C film. The field emission properties were promoted by higher substrate temperatures. Furthermore N-doped a-C film exhibits more field emission property than that of undoped a-C film. These results are explained as change of surface morphology and structural properties of a-C film.

• ETRI Journal
• /
• 제27권5호
• /
• pp.545-550
• /
• 2005

We have carried out the fabrications of a barrier layer on a polyethersulfon (PES) film and organic light emitting diode (OLED) based on a plastic substrate by means of atomic layer deposition (ALD). Simultaneous deposition of 30 nm $AlO_x$ film on both sides of the PES film gave a water vapor transition rate (WVTR) of $0.062 g/m^2/day (@38^{\circ}C,\;100%\;R.H.)$. Further, the double layer of 200 nm $SiN_x$ film deposited by plasma enhanced chemical vapor deposition (PECVD) and 20 nm $AlO_x$ film by ALD resulted in a WVTR value lower than the detection limit of MOCON. We have investigated the OLED encapsulation performance of the double layer using the OLED structure of ITO / MTDATA (20 nm) / NPD (40 nm) / AlQ (60 nm) / LiF (1 nm) / Al (75 nm) on a plastic substrate. The preliminary life time to reach 91% of the initial luminance $(1300 cd/m^2)$ was 260 hours for the OLED encapsulated with 100 nm of PECVD-deposited $SiN_x$ and 30 nm of ALD-deposited $AlO_x$.

• 인포메이션 디스플레이
• /
• 제15권2호
• /
• pp.16-24
• /
• 2014

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.195-196
• /
• 2009

This paper describes the fabrication and characteristics of polycrystalline 3C-SiC thin film diodes for extreme environment applications, in which the this thin film was deposited onto oxidized Si wafers by APCVD using HMDS In this work, the optimized growth temperature and HMDS flow rate were $1,100^{\circ}C$ and 8sccm, respectively. A Schottky diode with a Au, Al/poly 3C-SiC/$SiO_2$/Si(n-type) structure was fabricated and its threshold voltage ($V_d$), breakdown voltage, thickness of depletion layer, and doping concentration ($N_D$) values were measured as 0.84V, over 140V, 61nm, and $2.7{\times}10^{19}cm^2$, respectively. To produce good ohmic contact, Al/3C-SiC were annealed at 300, 400, and $500^{\circ}C$ for 30min under a vacuum of $5.0{\times}10^{-6}$Torr. The obtained p-n junction diode fabricated by poly 3C-SiC had similar characteristics to a single 3C-SiC p-n junction diode.

• 대한전자공학회논문지SD
• /
• 제44권2호
• /
• pp.7-12
• /
• 2007

고휘도 LED(Light-Emitting Diode)를 구현하기 위한 칩 설계의 최적화에 이용할 수 있는 SPICE 기반의 LED 3차원 회로 모델을 개발하였다. 본 모델은 LED를 일정한 면적의 픽셀로 구획하고, 각각의 픽셀은 n-전극, n-형 반도체, p-형 반도체, 및 p-전극 등의 일반적인 LED 레이어 구조를 반영하는 회로망으로 나타낸다. 개별의 박막 층과 접촉 저항은 저항 네트웍으로, pn-접합부는 일반적인 pn-접합 다이오드로 각각 모델링 한다. 별도의 테스트 패턴을 이용하여 독립적으로 추출한 파라미터를 이용한 시뮬레이션 결과는 실험 결과와 정확하게 일치함을 확인하였다.

• 한국전기전자재료학회논문지
• /
• 제11권4호
• /
• pp.314-320
• /
• 1998

In this study, we have investigated crystallization properties of $Te_x(Sb_{85}Ge_{15})_{100-x}$ (x=0.3, 0.5, 1.0) thin films prepared by thermal evaporation. The change of reflectance according to phase change from amorphous to crystalline phases with annealing and exposure of diode laser is measured b the n&k analyzer and the surface morphology between amorphous and crystalline phase is analyzed by SEM and AFM. The difference in reflectance($\DeltaR$) between amorphous and crystalline phase appears approximately 20% at the diode laser wavelength, 780nm in all prepared films. Especially, the reflectance difference,$\DeltaR$ comes up to about 30% in $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ thin film. Also, amorphous-to-crystalline phase change is observed in all prepared films. As a result of the measurement of the reflectance using diode laser, the reflectance is increased in proportion to the laser power and exposure time in all films. As a result of observing each film with the SEM and AFM, the surface morphology of the annealed and the exposed films are evidently increased than those of as-deposited films. The fast crystallization is occurred by increasing in Te content. Therefore, we conclude that the $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ and $Te_1(Sb_{85}Ge_{15})_{99}$ thin films can be evaluated as an attractive optical recording medium with high contast ratio and fast erasing time due to crystallization.

• Journal of Information Display
• /
• 제2권3호
• /
• pp.72-77
• /
• 2001

Amorphous silicon thin-film transistors (a-Si TFTs) were incorporated into Mo-tip-based triode-type field emitters and diode-type ones of carbon nanotubes for an active-matrix cathode (AMC) plate of field emission displays. Also, we developed a novel surface-treatment process for the Mo-tip fabrication, which gleatly enhanced in the stability of field emission. The field emission currents of AMC plates on glass substrate were well controlled by the gate bias of a-Si TFTs. Active-matrix field emission displays (AMFEDs) with these AMC plates were demonstrated in a vacuum chamber, showing low-voltage matrix addressing, good stability and reliability of field emission, and highly uniform light emissions from the anode plate with phosphors. The optimum design of AMFEDs including a-Si TFTs and a new light shield/focusing grid is discussed.

• 전기학회논문지
• /
• 제56권1호
• /
• pp.112-116
• /
• 2007

We have investigated the hysteresis phenomenon of a hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) and analyzed the effect of hysteresis phenomenon when a-Si:H TFT is a pixel element of active matrix organic light emitting diode (AMOLED). When a-Si:H TFT is addressed to different starting gate voltages, such as 10V and 5V, the measured transfer characteristics with 1uA at $V_{DS}$ = 10V shows that the gate voltage shift of 0.15V is occurred due to the different quantities of trapped charge. When the step gate-voltage in the transfer curve is decreased from 0.5V to 0.05V, the gate-voltage shift is decreased from 0.78V to 0.39V due to the change of charge do-trapping rate. The measured OLED current in the widely used 2-TFT pixel show that a gate-voltage of TFT in the previous frame can influence OLED current in the present frame by 35% due to the change of interface trap density induced by different starting gate voltages.

• 한국전기전자재료학회논문지
• /
• 제16권1호
• /
• pp.60-64
• /
• 2003

In this study, the inorganic thin-film passivation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam evaporation system, the various kinds of inorganic thin-films were deposited onto the organic layer and their interface properties between organic and inorganic layer were investigated. In this investigation, the MgO layer showed the most suitable properties, and based on this result, the time dependent emission properties were estimated for the OLED with and without passivation layer. In this experiment, we can see that the time-dependent emission properties of MgO passivated OLED had longer life-time compared to non-passivated OLED. Therefore, we can consider that the MgO thin film is one of the most suitable candidates for the thin-film passivation layer of OLED.