• 한국결정성장학회지
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• 제31권2호
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• pp.73-77
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• 2021

RF 마그네트론 스퍼터링 공정에 의해 Ga-doped ZnO 박막이 O2 및 Ar 분위기 하에서 증착 조건에 따라 합성되었으며, N2 분위기에서, 600℃에서 급속열처리(RTA)를 실시하였다. 증착된 ZnO : Ga 박막에 대해 두께를 측정하였고, XRD 패턴 분석에 의해 결정상을 조사하였으며, FE-SEM, AFM 이미지에 의해 박막의 미세구조를 관찰하였다. O2 및 Ar 분위기 기체 종류별로 형성된 박막들의 증착 조건에 따라 X-선 회절 패턴의 (002)면의 세기는 상당한 차이를 나타냈다. O2 조건에서는 Ga doping이 이루어진 단일 박막의 경우에서는 강한 세기의 회절피크가 관찰되었다. O2 및 Ar 조건에서는 Ga doping이 이루어진 다층박막의 경우에서는 다소 약한 세기의 (002) 면의 피크만을 나타내었다. FE-SEM image에서는 박막의 표면입자의 크기는 두께가 증가함에 따라 입자크기가 다소 증가하는 것으로 관찰되었다. O2 및 Ar 분위기 조건 하에서, Ga doping이 이루어진 다층박막의 경우에서는, 비저항은 6.4 × 10-4Ω·cm을 나타냈고, O2 분위기 조건하에서, Ga doping이 이루어진 단일 박막의 경우에서는 저항값이 감소하였고, Ga-doped ZnO 박막의 두께가 2 ㎛로 증가하면서 저항이 감소하였으며, 1.0 × 10-3 Ω·cm의 비교적 낮은 비저항 값을 나타내었다.

• The Korean Journal of Ceramics
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• 제3권2호
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• pp.134-138
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• 1997

$Dy^{3+}-(or Tm^{3+}-)$ doped $Ga_2O_3 \;and\; ZnGa_2O_4$ phosphors were prepared using the solid state reaction method to investigate their photoluminescent characteristics. Under 254 nm excitation, $Dy^{3+}-doped Ga2_O_3$ exhibited two emission bands of 460~505nm and 570~600nm. On the other hand, $Dy^{3+}-(or Tm^{3+}-)$ doped $ZnGa_2O_4 $phosphors exhibited a broad-band emission extending from 330 nm to 610 nm, peaking at about 430 nm(or 370 nm). In this study, an emission peak shift of nealy 50 nm towards longer wavelength region was observed with $Dy^{3+}$ doping in the $ZnGa_2O_4 $.

• 한국진공학회지
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• 제1권2호
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• pp.254-258
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• 1992

Iodine 화학수송법으로 성장한 Ni-doped CdGa2Se4와 undoped CdGa2Se4 단결정 의 PL 및 PLE 스펙트럼을 조사하였다. Undoped CdGa2Se4 단결정의 PL 스펙트럼에서는 전도대아래 준 연속적으로 분포된 electron trap과 deep level, 그리고 가전자대 위 0.07eV, 0.12eV에 있는 acceptor level 사이의 전자전이에 의한 2개의 emission band를 2.13eV와 1.20eV 영역에서 관측하였으며, Ni-doped 단결정에서는 Ni2+ 이온의 여기상태 3T1(3P)와 바 닥상태 3T1(3F) 사이의 전자전이에 의한 emission band를 1.48eV 영역에서 관측하였다. 이 러한 결과로부터 제안된 CdGa2Se4의 energy band model은 본 연구의 PL mechanism을 설명하는데 가능함을 보여주었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.66-69
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• 1997

The p-GaN fins doped with the impurity of Zn were grown on n-GaN films to prevent the defects from the lattice mismatch with sapphire substrates by HVPE. For growth of the high quality n-GaN, the optimized conditions were at first deduced from the results of various HCI gas flow rates and growth temperatures. On the basis of these conditions, p-GaN films were grown and investigated of the characteristics. The FWHM of the double crystal rocking curve of n-GaN was decreased and the hexagonal phases on the surface of GaN films were tend to be vivid with the inoement of HCI gas flow rates. Finally the n-type GaN films with FWHM of 648arcsec were obtained at 10cc/min of HCI gas. As the GaN films were grown with the above conditions, Zn was introduced in the form of vapor as a dopant for p-GaN films. But when Zn vaporized at 77$0^{\circ}C$ was doped to the films, the crystallites of Zn were distributed uniformly on the surface of the GaN film due to the over-doped.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.759-762
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• 2003

The epitaxially grown Mg-doped GaN thin film was prepared by MOCVD (Metal Organic Chemical Vapor Deposition) for a SAW(Surface Acoustic Wave) filter. Mg-doped GaN thin film had enough properties for a SAW filter which include crystallinity and morphology. The surface morphology and crystalline of the Mg-doped GaN thin films were characterized using AFM and an X-ray rocking curve. The SAW filter, which was fabricated by lift-off process and frequency response, was measured by HP 8753C network analyzer. Center frequency was 96.687 MHz and SAW velocity was 5801 m/s when wavelength(λ) was 60${\mu}{\textrm}{m}$. Insertion loss was over -10 dB, Q was factor over 200, and side lobe attenuation was over 22 dB which was suitable for use as a SAW filter. Electro-mechanical coupling coefficient (k$^2$) was calculated from the measured data. k$^2$ was from 1 % to 1.44 %. The fabricated SAW filter using Mg-doped GaN/sapphire structure has good qualities as a filter and will be used as a SAW filter for operating RF frequency.

• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.11-15
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• 2016

This paper, Ga-doped ZnO (GZO) thin films which were deposited on Corning glass substrate using an magnetron sputtering deposition technology and then the post deposition annealing process was conducted for 30 minutes at different temperature of 100, 200, 300, and $400^{\circ}C$, respectively. So as to investigate the properties for the relevant the Concentration and Oxygen Vacancy with Annealing temperature of Ga-doped ZnO thin films by RF Sputtering method. The Carrier concentration is enhanced as annealing temperature decreases, and also the oxygen vacancy concentration is enhanced as annealing temperature decreased. Oxygen vacancy will decrease along with Carrier concentration. This change in Carrier concentration is related to changes in oxygen vacancy concentration. The figure of merit obtained in this study means that Ga-doped ZnO films which annealed at $400^{\circ}C$ have the lowest Carrier concentration and Oxygen vacancy, which have the highest optoelectrical performance that it could be used as a transparent electrode.

• Transactions on Electrical and Electronic Materials
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• 제15권5호
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• pp.262-264
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• 2014

Pristine ZnO, 3 wt.% Ga-doped (3GZO) and 3 wt.% Ag-doped (3SZO) ZnO nanowires (NWs) were grown using the hot-walled pulse laser deposition (HW-PLD) technique. The doping of Ga and Ag in ZnO NWs was observed by analyzing the optical and chemical properties. We optimized the synthesis conditions, including processing temperature, time, gas flow, and distance between target and substrate for the growth of pristine and doped ZnO NWs. The diameter and length of pristine and doped ZnO NWs were controlled under 200 nm and several ${\mu}m$, respectively. Low temperature photoluminescence (PL) was performed to observe the optical property of doped NWs. We clearly observed the shift of the near band edge (NBE) emission by using low temperature PL. In the case of 3GZO and 3SZO NWs, the center photon energy of the NBE emissions shifted to low energy direction using the Burstein Moss effect. A strong donor-bound exciton peak was found in 3 GZO NWs, while an acceptor-bound exciton peak was found in 3SZO NWs. X-ray photoelectron spectroscopy (XPS) also indicated that the shift of binding energy was mainly attributed to the interaction between the metal ion and ZnO NWs.

• Transactions on Electrical and Electronic Materials
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• 제11권1호
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• pp.37-41
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• 2010

The authors investigated the photoluminescence (PL) and the electron paramagnetic resonance (EPR) from an magnesium (Mg)-doped GaN thin film with a delta-doped layer. The regularly doped sample shows a PL peak at 2.776 eV for the as-grown sample, and the peak shifts to 2.904 eV and increases in intensity for the annealed sample. The delta-doped sample also shows the same PL peak as does the regularly doped sample. However, only the annealed delta-doped layer shows a sharp EPR with a small isotropic Lande g-factor, $g_{II}$, of 2.029. This resonance is attributed to the delta-doped layer, which forms a hole-bound Mg-N atomic structure instead of the $Mg_{Ga}-V_N$ defect complex, indicating that the delta-doped sample was not optically activated to form PL centers but was instead electrically activated to form a hole-bound state.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.414-414
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• 2008

Vertically well-aligned Ga-doped ZnO nanorods with different Ga contents were grown by thermal evaporation on a ZnO template. The Ga-doped ZnO nanorods synthesized with 50 wt % Ga with respect to the Zn content showed maximum compressive stress relative to the ZnO template, which led to a rapid growth rate along the c-axis due to the rapid release of stored strain energy. A further increase in the Ga content improved the conductivity of the nanorods due to the substitutional incorporation of Ga atoms in the Zn sites based on a decrease in lattice spacing. The p-n diode structure with Ga-doped ZnO nanorods, as a n-type, displayed a distinct white light luminescence from the side-view of the device, showing weak ultraviolet and various deep-level emissions.

• 한국정보통신학회논문지
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• 제16권3호
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• pp.558-564
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• 2012

Sol-gel 법으로 Eagle 2000 유리 기판 위에 Ga 도핑 농도와 열처리 온도에 따른 GZO 박막을 제작하여, 전기적 및 광학적 특성을 조사하였다. 1 mol% Ga 이 도핑되고 $600^{\circ}C$에서 열처리한 GZO 박막에서 가장 우수한 (002) 배향성이 관찰되었다. Hall 측정 결과, Ga 도핑 농도가 증가함에 따라 segregation 효과로 인한 캐리어 농도의 감소와 비저항 값의 증가가 관찰되었다. 1 mol% Ga 이 도핑되고 $600^{\circ}C$에서 열처리한 GZO 박막에서 가장 큰 캐리어 농도($9.13{\times}10^{18}cm^{-3}$)와 가장 낮은 비저항 ($0.87{\Omega}cm$) 값을 나타내었다. 모든 박막은 가시광 영역에서 약 80 % 이상의 투과율을 보였으며, Ga 농도가 1 에서 4 mol% 로 증가함에 따라 에너지 밴드 갭이 좁아지는 Burstein-Moss 효과가 관찰되었다.