비정질실리콘 MIS 캐패시터의 C - V 특성

박혁렬,이석호 한국진공학회 2001 한국진공학회 학술발표회초록집 Vol.- No.-

RF 글로우 방전에 의한 PIN형 비정질규소 태양전지의 제작과 P층의 최적두께 결정

박혁렬 木浦大學校基礎科學硏究所 1984 基礎科學硏究誌 Vol.2 No.-

Thin film amorphous silicon solar cell in PIN structure has been fabricated and the effects of p-layer thickness on photovoltaic properties were investigated. The sample were prepared by RF glow discharge decomposition of silane, silane+phosphine and sillane+diborane mixture. The optimum p-layer thickness is about 100Å. The absorption in p-layer is a dominant factor to decreased the conversion efficiency.

비정질 실리콘 반도체에서 밴드갭이하 광흡수 스펙트럼에 대한 측정온도의 효과

김영문,문기영,박혁렬 木浦大學校 基礎科學硏究所 1992 基礎科學硏究誌 Vol.10 No.-

We have investigated the effects of measurement temperature on sub-band gap optical absorption coefficient of hydrogenated amorphous silicon (a-Si : H) films by the optical transmission and CPM(constant photocurrent method) measurement. We have found almost no change of the slope in exponential tail region of the absorption coefficient spectrum, with increasing measurement temperatures from about 20 to 150℃. When the full optical absorption spectrum was established from the match of the transmission and the full CPM spectrum at each temperatures, the magnitude of the deep defect related absorption coefficients is essentially unchanged. From these results, we have speculated the effects of measurement temperatures on the density of state spectrum kin a-Si : H.

수소화된 비정질 규소박막의 정상상태 광전기 전도도 측정에 의한 재결합 과정의 연구

박혁렬,이주천 木浦大學校基礎科學硏究所 1985 基礎科學硏究誌 Vol.3 No.-

Steady-state photoconductivity measurements are made on thin films of hydrogenated amorphous silicon(a-Si-:H) prepared by RF glow discharge of silane(SiH₄) as a function of temperatures and excitation light intensities. The experimental results are explained on the basis of the proposed recombination model considering at least two set of localized states in addition to the extended electron and hole states.

팔랴듐/비정질 규소 쇼트키 다이오드의 제작과 전기용량-전압 실험에 의한 금지대내 상태밀도 결정

박혁렬,정해문,김창대 木浦大學校基礎科學硏究所 1984 基礎科學硏究誌 Vol.2 No.-

Hydrogenated amorphous silicon(a-Si:H) Schottky diodes have been prepared by glow discharge decomposition of SiH₄on stainless steel substrate, and vacuum evaporation of Pd. Various diode parameters were investigated from dark current-voltage characteristics, also from the capacitance-voltage measurements versus frequency, electronic density of states distribution N(E) is determined. The main feature of N(E) is determined (1) The density of states around Fermi-level ?? is about ??, (2) The density of states near conduction band edge is about ??, (3) No pdak in the density of states in the gap shows up.

PECVD로 제작한 수소화된 비정질 탄소(a-C:H) 박막의 광학적에너지 갭과 전기전도도

박혁렬,이석호,오동선,홍선화 木浦大學校基礎科學硏究所 1996 基礎科學硏究誌 Vol.14 No.-

Hydrogenated amorphous carbon(a-C:H) films were deposited onto glass or Si-wafer substrate from CH₄ gas by using PECVD(plasma Enhanced Chemical Vapor Deposition) method. The films were deposited at various substrate temperatures and two different position of the substrate. The optical and electrical properties of the deposited films were characterized by measuring such as UV/VIS transmission spectrum, FTIR absorption spectrum and dark electrical conductivity. We found a decreased in deposition rate and optical energy gap as the substrate temperature was increased. The deposition rate was increased for the films deposited at IS(ion-sheath) region than at BP(bulk-plasma) region, while the optical energy gap was increased for the films deposited at BP than at IS region. We obtained a very hard diamond-like-carbon(DLC) films at IS region and in optimal substrate temperature. The films showed a thermally activated conduction with an activation energy of about 0.24 eV above 400 K, while a variable range hopping conduction below about 400 K.

Impurity content and the light-induced stability in a-Si:H

Park, Hyuk Ryeol 木浦大學校 基礎科學硏究所 1995 基礎科學硏究誌 Vol.13 No.-

In an earlier study of 37 a-Si:H films we identified positive correlations between the saturated light-induced defect density ??, the hydrogen content ?? measured by IR absorption, and the optical gap. Impurities also have been implicated in the production of metastable defects. This situation led us to analyze our samples for impurity content. Our present 42 samples of H, B, C, N, O, F, Na, Cr, and Ge were determined secondary ion mass spectroscopy. Na, Cr, or Ge were not detected. The content of C, N and O varies by a factor ∼1,000 and depends on deposition system and source gas. We report a comprehensive evaluation of our data with emphasis on their correlation with optoelectronic properties. We find the annealed state defect density ?? and the saturated light-induced defect density ?? surprisingly independent of impurity content.

The saturated light-induced defect density and the growth rate of light-induced defects in a-Si:H

Park, Hyuk-Ryeol 木浦大學校 基礎科學硏究所 1995 基礎科學硏究誌 Vol.13 No.-

We studied the relationship between the growth rate of light-induced defects in a-Si:H, dNs/dt, and the saturated defect density ??. The dNs/dt values measured at a typical solar generation rate(??) are clearly correlated with ??. Therefore, ?? may be employed to predict the usable life of a-Si:H.

반도체박막에서 빛 투과도 스펙트럼과 빛의 이중성

임태현,박혁렬 한국물리학회 2010 새물리 Vol.60 No.8

We show that both the particle and the wave nature of light can be shown simultaneously in the light transmittance spectra of semiconductor thin films. The interference fringe in the range of γ = 700 ~ 1500 nm in an amorphous silicon thin film of about 1 μm in thickness is due to the formation of a standing wave and represents the wave nature of light. In addition, the rapid decrease in the transmittance below γ = 700 nm is due to the emission of an electron from a bonding to a free state by absorbing photon energy and represents the particle nature of light. The film thickness calculated from the interference fringe is a parameter of the wave nature of light, and the magnitude of the energy gap obtained from the absorption spectrum is a parameter of the particle nature of light. 비정질 실리콘 반도체 박막에 대한 빛 투과도 스펙트럼을 통해 빛의이중성 즉 파동성과 입자성이 동시에 설명될 수 있음을 소개하였다. 두께1 ㎛ 정도인 비정질 실리콘 박막의 빛 투과도 스펙트럼 중 γ = 700 ~ 1500 nm 구간에서 나타나는 간섭무늬는 박막 내부에 형성된 정상파에 의한 것으로 이는 빛의 파동성을 보여주는 현상이고 반면 γ ≤ 700 nm 구간에서 나타나는 투과도의 급격한 감소는 비정질 실리콘에서 공유결합상태에 있던 전자가 포톤 에너지를 흡수하여자유전자로 방출되는 것으로 이는 빛의 입자성을 보여주는 현상이다. 간섭무늬로부터 구해지는 박막의 두께는 파동현상을 대표하는 변수이고반면 흡수 스펙트럼에서 구해지는 에너지 갭의 크기는 입자현상을 대표하는 변수이다.

반도체와 태양전지의 효과적인 교육을 위한 보완적 교수학습자료

최지애,박혁렬 한국물리학회 2016 새물리 Vol.66 No.7

We suggest complementary teaching materials for effective education on semiconductors and solar cells in high school. Differences in electrical properties of metals and semiconductors were explained by focusing on the differences in the chemical bond properties of the two types of materials. The position of the Fermi level in a semiconductor was explained as the average value of the electrical potential energies of electrons in the valence, conduction, donor, and acceptor states. A schematic diagram that included both the point of view of the electron and the hole was introduced, so that students could more accurately understand the movement of electrons and holes under the load-operating condition of a solar cell. We also introduce an apparatus that can be prepared simply and inexpensively for measuring the efficiencyt of a cell. The result of using the developed tools with high-school students in a local city is presented. 반도체 및 태양전지와 관련하여 현행 고등학교 교과서에 소개되고 있는 내용들을 보완할 수 있는 교수학습자료를 제시하였다. 금속과 반도체의 전기전도성의 차이를 두 물질간의 화학결합특성의 차이를 중심으로 설명하는 방법을 제시하였다. 순수, P형, N형 반도체에서 페르미 준위의 위치를 전기위치에너지의 평균값 개념을 사용하여 설명하였다. 태양전지에서 전자와 정공의 거동을 전자의 관점과 정공의 관점 모두를 포함하는 모식도를 제시함으로써 학생들이 전자와 정공의 운동을 보다 정확히 이해할 수 있도록 했다. 아울러 손쉽고 저렴하게 제작할 수 있는 태양전지 효율측정장치를 소개한다. 개발한 자료를 고등학생들에게 적용한 결과도 소개한다.