• 제목/요약/키워드: amorphous/crystalline Si

검색결과 227건 처리시간 0.028초

Strain measurement in the interface between crystalline Silicon and amorphous Silicon with MEIS

  • Yongho Ha;Kim, Sehun;Kim, H.K.;D.W. Moon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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    • pp.178-178
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    • 1999
  • Low temperature Si epitaxy can provide flexibility for a device designer to tailor or optimize the device performance. It is better method for controlling the doping thickness, concentration and profile than ion implantation and diffusion. But there is a limited growth thickness in this method. At a given temperature, the film grows epitaxially for a certain limiting thickness(hepi) and becomes amorphous. The transition from crystalline Si to amorphous Si is abrupt. In this study, Si film was deposited by ion beam sputter deposition on Si (0001) above a limiting thickness and measure the strain in the interface between crystalline Si and amorphous Si. The strain was compressive and the maximum value was about 2%.

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다공성실리콘 위의 탄화규소 박막의 증착 및 발광특성 (Deposition and Photoluminescence Characteristics of Silicon Carbide Thin Films on Porous Silicon)

  • 전희준;최두진;장수경;심은덕
    • 한국세라믹학회지
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    • 제35권5호
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    • pp.486-492
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    • 1998
  • Silicon carbide (SiC) thin films were deposited on the porous silicon substrates by chemical vapour de-position(CVD) using MTS as a source material. The deposited films were ${\beta}$-SiC with poor crystallity con-firmed by XRD measurement. It was considered that the films showed the mixed characteistics of cry-stalline and amorphous SiC where amorphous SiC where amorphous SiC played a role of buffer layer in interface between as-dep films and Si substrate. The buffer layer reduced lattice mismatch to some extent the generally occurs when SiC films are deposited on Si. The low temperature (10K) PL (phtoluminescence) studies showed two broad bands with peaks at 600 and 720 for the films deposited at 1100$^{\circ}C$ The maximum PL peak of the crystalline SiC was observed at 600 nm and the amrophous SiC of 720 nm was also confirmed. PL peak due the amorphous SiC was smaller than that of the crystalline SiC, PL of porous Si might be disapperared due to densification during heat treatment.

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Synthesis and Optoelectronic Characteristics of Single-crystalline Si Nanowires

  • Kim, Kyung-Hwan;Keem, Ki-Hyun;Kang, Jeong-Min;Yoon, Chang-Joon;Jeong, Dong-Young;Min, Byung-Don;Cho, Kyoung-Ah;Kim, Hyun-Suk;Kim, Sang-Sig
    • Transactions on Electrical and Electronic Materials
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    • 제6권5호
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    • pp.198-201
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    • 2005
  • Photocurrent of a single-crystalline Si nanowire is investigated in this paper. Single-crystalline Si nanowires with amorphous $SiO_2$ shells were first synthesized from ball-milled SiO powders by thermal chemical vapor deposition, and then the amorphous $SiO_2$ shells were etched out from the as-synthesized Si nanowires. For a single-crystalline Si nanowire, photocurrent-voltage curves taken in air at room temperature were non-linear, and rapid photoresponses were observed when the light was switched on and off. The photocurrent was not changed in intensity under the illumination. Photocurrent mechanism in the single-crystalline Si nanowire is discussed in this paper.

단일 Si 나노선 합성 및 광특성 연구 (Synthesis and photoresponse characteristics of single-crystalline Si nanowires)

  • 김경환;김기현;강정민;윤창준;정동영;민병돈;조경아;김현석;김상식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.81-83
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    • 2005
  • Photocurrent of a single-crystalline Si nanowire is investigated in this paper. Single-crystalline Si nanowires with amorphous $SiO_2$ shells were first synthesized from ball-milled SiO powders by thermal chemical vapor deposition, and then the amorphous $SiO_2$ shellswere etched out from the as-synthesized Si nanowires. For a single-crystalline Si nanowire, photocurrent-voltage curves taken in air at room temperature were non-linear, and rapid photoresponses were observed when the light was switched on and off. The photocurrent was not changed in intensity under the illumination. Photocurrent mechanism in the single-crystalline Si nanowire is discussed in this paper.

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Low temperature solid phase crystallization of amorphous silicon thin film by crystalline activation

  • Kim, Hyung-Taek;Kim, Young-Kwan
    • Journal of Korean Vacuum Science & Technology
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    • 제2권2호
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    • pp.97-100
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    • 1998
  • We have investigated the effects of crystalline activation on solid phase crystallization (SPC) of amorphous silicon (a-Si) thin films. Wet blasting and self ion implantation were employed as the activation treatments to induce macro or micro crystalline damages on deposited a-Si films. Low temperature and larger grain crystallization were obtained by the applied two-step activation. High degree of crystallinity was also observed on both furnace and rapid SPC. crystalline activations showed the promotion of nucleation on the activated regions and the retardation of growth in an amorphous matrix in SPC. The observed behavior of two-step SPC was strongly dependent on the applied activation and annealing processes. It was also found that the diversified effects by macro and micro activations on the SPC were virtually diminished as the annealing temperature increased.

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Crystallization of Forsterite Xerogel under Carbon Dioxide: A New Crystalline Material Synthesized by Homogeneous Distribution of Carbonaceous Component into Forsterite Xerogel

  • 송미영;김수주;권혜영;박선희;박동곤;권호진;권영욱;James M. Burlitch
    • Bulletin of the Korean Chemical Society
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    • 제20권5호
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    • pp.517-524
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    • 1999
  • By heating the magnesiumsilicate (Mg2SiO4:forsterite) xerogel in carbon dioxide, carbonaceous component was intentionally introduced into the amorphous solid precursor. Carbon was introduced homogeneously as unidentate carbonate. Upon being heated at 800 。C in carbon dioxide, the xerogel which had homogeneously distributed carbonaceous component in it crystallized into a single phase product of a new crystalline material, which had approximate composition of Mg8Si4Ol8C. The powder X-ray diffraction pattern of the new crystalline material did not match with any known crystalline compound registered in the powder diffraction file. Crystallization from amorphous xeroget to the new crystalline phase occurred in a very narrow range of temperature, from 750 。C to 850 。C in carbon dioxide, or in dty oxygen. Upon being heated above 850 。C, carbonaceous component was expelled from the product, accompanied by irreversible transition from the new crystalline material to forsterite.

공기 중에서 자기장 열처리된 CoFeSiB 비정질 리본에서의 자기 바이어스 효과 (Magnetic Bias Effects in Field-annealed CoFeSiB Amorphous Ribbons)

  • 차용준;정종율;김철기;김동영;윤석수
    • 한국자기학회지
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    • 제19권6호
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    • pp.191-196
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    • 2009
  • 비대칭 거대 자기임피던스 효과를 보이는 자기장 열처리된 CoFeSiB 비정질 리본에서 자기 바이어스 현상을 MOKE 방법을 이용하여 연구하였다. 열처리 과정에서 리본의 양 표면에 형성된 경자성 결정층이 내부 연자성 비정질 상의 자화특성에 미치는 영향을 조사하기 위해 열처리 후 화학적 에칭에 의해 한쪽 및 양쪽 표면의 결정층을 깎아낸 시편들을 준비하고 각 시편에 대해 비정질 상의 자화곡선을 MOKE 방법으로 측정하였다. 열처리 과정에서 표면에 형성된 경자성층이 내부의 비정질 연자성 상에 바이어스 자기장을 작용하고 있다는 것과 바이어스 자기장의 방향이 경자성층의 자화방향에 반대 방향임을 자기이력곡선의 이동을 통해 확인하였다.

Thin Film Amorphous/Bulk Crystalline Silicon Tandem Solar Cells with Doped nc-Si:H Tunneling Junction Layers

  • 이선화;이준신;정채환
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.257.2-257.2
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    • 2015
  • In this paper, we report on the 10.33% efficient thin film/bulk tandem solar cells with the top cell made of amorphous silicon thin film and p-type bulk crystalline silicon bottom cell. The tunneling junction layers were used the doped nanocrystalline Si layers. It has to allow an ohmic and low resistive connection. For player and n-layer, crystalline volume fraction is ~86%, ~88% and dark conductivity is $3.28{\times}10-2S/cm$, $3.03{\times}10-1S/cm$, respectively. Optimization of the tunneling junction results in fill factor of 66.16 % and open circuit voltage of 1.39 V. The open circuit voltage was closed to the sum of those of the sub-cells. This tandem structure could enable the effective development of a new concept of high-efficiency and low cost cells.

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N-Type c-Si 이종접합 태양전지 제작을 위한 a-Si:H(p) 가변 최적화 (A Study of Optimization a-Si:H(p) for n-type c-Si Heterojunction Solar Cell)

  • 허종규;윤기찬;최형욱;이영석;;김영국;이준신
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.77-79
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    • 2009
  • Amorphous/crystalline silicon heterojunction solar cells, TCO/a-Si:H (p)/c-Si(n)/a-Si:H(n)/Al, are investigated. The influence of various parameters for the front structures was studied. We used thin (10 nm) a-Si:H(p) layers of amorphous hydrogenated silicon are deposited on top of a thick ($500{\mu}m$) crystalline c-Si wafer. This work deals with the influence of the a-Si:H(p) doping concentration on the solar cell performance is studied.

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