RF Power에 따른 태양전지용 N-type ZnS 특성연구

양현훈,김한울,정운조,이석호,소순열,박계춘,이진,정해덕,Yang, Hyeon-Hun,Kim, Han-Wool,Jeong, Woon-Jo,Lee, Suk-Ho,So, Soon-Youl,Park, Gye-Choon,Lee, Jin,Chung, Hea-Duck 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.7

In this study, we use the $2.5cm{\times}7.5cm$ soda lime glass as the substrate. We used the ultrasonicator. Glass was dipped in the acetone, methanol and DI water respectively for 10 minutes. Ar(99.99%)gas was used as the sputtering gas. We varied the RF power between 100~175 W with 25 W steps. Base pressure was kept by turbo molecular pump at $3.0{\times}10^{-6}$ torr. Working pressure was kept by injection of Ar gas. ZnS thin films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers. It is also clearly observed that, the intensity of the (111) XRD peak increases with increasing the RF power. Electrical properties were measured by hall effect methods at room temperature. The resistivity, carrier concentration, and hall mobility of ZnS deposited on glass substrate as a function of sputtering power. It can be seen that as the sputtering power increase from 100 to 175 W, the resistivity of the films on glass decreased significantly from $8.1{\times}10^{-2}$ to $1.2{\times}10^{-3}\;{\Omega}{\cdot}cm$. This behavior could be explained by the effect of the sputtering power on the mobility and carrier concentration. When the RF power increases, the carrier concentration increases slightly while the resistivity decreases significantly. These variation originate from improved crystallinity and enhanced substitutional doping as the sputtering power increases.

Cu/In 비에 따른 CuInS₂ 박막의 특성에 관한 연구

양현훈,박계춘,Yang, Hyeon-Hun,Park, Gye-Choon 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.7

[ $CulnS_2$ ] thin films were synthesized by sulfurization of Cu/In Stacked elemental layer deposited onto glass Substrates by vacuum furnace annealing at temperature $200^{\circ}C$. And structural and electrical properties were measured in order to certify optimum conditions for growth of the ternary compound semiconductor $CuInS_2$ thin films with non-stoichiometry composition. $CuInS_2$ thin film was well made at the annealed $200^{\circ}C$ of SLG/Cu/In/S stacked elemental layer which was prepared by thermal evaporator, and chemical composition of the thin film was analyzed nearly as the proportion of 1 : 1 : 2. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM and Hall measurement system. The compositional deviations from the ideal chemical formula for $200^{\circ}C$ material can be conveniently described by non-molecularity$({\Delta}x=[Cu/In]-1)$ and non-stoichiometry $({\Delta}y=[{2S/(Cu+3In)}-1])$. The variation of ${\Delta}x$ would lead to the formation of equal number of donor and accepters and the films would behave like a compensated material. The ${\Delta}y$ parameter is related to the electronic defects and would determine the type of the majority charge carriers. Films with ${\Delta}y>0$ would behave as p-type material while ${\Delta}y<0$ would show n-type conductivity. At the sane time, carrier concentration, hall mobility and resistivity of the thin films was $9.10568{\times}10^{17}cm^{-3},\;312.502cm^2/V{\cdot}s\;and\;2.36{\times}10^{-2}\;{\Omega}{\cdot}cm$, respectively.

기판온도와 열처리 온도에 따른 CuInSe₂ 박막의 특성분석

양현훈,정운조,박계춘,Yang, Hyeon-Hun,Jeong, Woon-Jo,Park, Gye-Choon 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.7

Process variables for manufacturing the $CuInSe_2$ thin film were established in order to clarify optimum conditions for growth of the thin film depending upon process conditions (substrate temperature, sputtering pressure, DC/RF Power), and then by changing a number of vapor deposition conditions and Annealing conditions variously, structural and electrical characteristics were measured. Thereby, optimum process variables were derived. For the manufacture of the $CuInSe_2$, Cu, In and Se were vapor-deposited in the named order. Among them, Cu and In were vapor-deposited by using the sputtering method in consideration of their adhesive force to the substrate, and the DC/RF power was controlled so that the composition of Cu and In might be 1 : 1, while the surface temperature having an effect on the quality of the thin film was changed from $100^{\circ}C\;to\;300^{\circ}C$ at intervals of $50^{\circ}C$. The diffract fringe of X-ray, which depended upon the substrate temperature and the Annealing temperature of the manufactured $CuInSe_2$ thin film, was investigated. scanning electron microgaphs of represents a case that a sample manufactured at the substrate temperature of $100^{\circ}C$ was thermally treated at $200{\times}350^{\circ}C$. As a result, at $500^{\circ}C$ of the Annealing temperature, their chemical composition was measured in the proportion of 1 : 1 : 2. It could be known that under this condition, the most excellent thin film was formed, compared with the other conditions.

태양전지용 MgF₂ 반사방지막 특성연구

양현훈(Hyeon-Hun Yang),백수웅(Su-Ung Baek),나길주(Kil-Ju Na),소순열(Soon-Youl So),박계춘(Gye-Choon Park),이진(Jin Lee),정해덕(Hae-Deok Chung) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7

MgF₂ is a current material for the optical applications in the UV and deep UV range. Process variables for manufacturing the MgF₂ thin film were established in order to clarify optimum conditions for growth of the thin film depending upon process conditions , and then by changing a number of vapor deposition conditions and substrate temperature, Annealing conditions variously, structural and Optical characteristics were measured. Thereby, optimum process variables were derived. Nevertheless, modern applications still require improvement of the optical and structural quality of the deposited layers. In the present work, the composition and microstructure of MgF₂ single layers grown on slide glass substrate by Electro beam Evaporator(KV-660) processes, were analyzed and compared. The surface Substrate temperature having an effect on the quality of the thin film was changed from 200[℃] to 350[℃] at intervals of 50[℃]. and annealing temperature an effect on the thin film was changed from 200[℃] to 400[℃] at intervals of 50[℃]. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM.

Non-linear optical properties of PECVD nanocrystal-Si nanosecond excitation

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),김주회(Kim, Joo Hoe),김철중(Kim, Chul Joong),이창권(Lee, Chang Gwon) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

A study of the non-linear optical properties of nanocrystal-Si embedded in SiO2 has been performed by using the z-scan method in the nanosecond and femtosecond ranges. Substoichiometric SiOx films were grown by plasma-enhanced chemical-vapor deposition(PECVD) on silica substrates for Si excesses up to 24 at/%. An annealing at 1250?C for 1 hour was performed in order to precipitate nanocrystal-Si, as shown by EFTEM images. Z-scan results have shown that, by using 5-ns pulses, the non-linear process is ruled by thermal effects and only a negative contribution can be observed in the non-linear refractive index, with typical values around -10-10cm²/W. On the other hand, femtosecond excitation has revealed a pure electronic contribution to the nonlinear refractive index, obtaining values in the order of 10-12 cm2/W. Simulations of heat propagation have shown that the onset of the temperature rise is delayed more than half pulse-width respect to the starting edge of the excitation. A maximum temperature increase of {Delta}T=123.1?C has been found after 3.5ns of the laser pulse maximum. In order to minimize the thermal contribution to the z-scan transmittance and extract the electronic part, the sample response has been analyzed during the first few nanoseconds. By this method we found a reduction of 20% in the thermal effects. So that, shorter pulses have to be used obtain just pure electronic nonlinearities.

A Study on properties of a-Si:H layers by photoelectron spectroscopic

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),김주회(Kim, Joo Hoe),김철중(Kim, Chul Joong),이창권(Lee, Chang Gwon),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

We report on a detailed study on gap-state distribution in thin amorphous silicon layers(a-Si:H) with film thickness between 5 nm and 20 nm c-Si wafers performed by UV excited photoelectron spectroscopy(UV-PES). We measured how the work function, the gap state density, the position of the Fermi-level and the Urbch-energy depend on the layer thickness and the doping level of the ultra thin a-Si:H(n) layer. It was found, that for phosphorous doping the position of the Fermi level saturates at E_F-E_V=1.47 eV. This is achieved at a gas phase concentration of 10000 ppm PH₃ in the SiH₄/H₂ mixture which was used for the PECVD deposition process. The variation of the doping level from 0 to 20000 ppm PH₃ addition results in an increase of the Urbach energy from 65 meV to 101 meV and in an increase of the gap state density at midgap(E_i-E_V=0.86eV) from 3{times}10^{18} to 2{times}1019cm^{-3}eV^{-1}.

A Study on Properites of PV Solar cell n-type ZnS Using RF Sputtering Method

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),한창준(Han, Chang-Jun),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin),정해덕(Chung, Hea-Deok),이석호(Lee, Suk-Ho),백수웅(Back, Su-Ung),나길주(Na, Kil-Ju),정운조(Jeong, Woon 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05

ZnS thin films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers. With the increase in the deposition temperature and the decrease in the radio frequency sputtering power, the crystallinity was increased and the surface roughness was decreased, which lead to the decrease in the electrical resistivity of the film. It is also clearly observed that, the intensity of the (111) XRD peak increases with increasing the substrate temperature. On the other hand, as seen in the FWHM decreased with increasing the substrate temperature. Since the FWHM of the (111) diffraction peak is inversely properties to the grain size of the film, then grain size of ZnS thin film increases with increasing the substrate temperature. The electrical resistivity and optical transmittance of the ZnS film as a function of the post-annealing temperature. It can be seen that with the annealing temperature set at 400?C, the resistivity decreases to a minimum value of 2.1{times}10^{-3};{Omega}cm and the transmittance increases to a maximum value of 80% of the ZnS film.

A Study on Properites of PV Solar cell AZO thin films post-annealing by RTP technique

양현훈(Yang, Hyeon-Hun),김한울(Kim, Han-Wool),한창준(Han, Chang-Jun),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin),정해덕(Chung, Hea-Deok),이석호(Lee, Suk-Ho),백수웅(Back, Su-Ung),나길주(Na, Kil-Ju),정운조(Jeong, Woon 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05

In this paper, ZnO:Al thin films with c-axis preferred orientation were prepared on Soda lime glass substrates by RF magnetron sputtering technique. AZO thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and substrate temperature conditions variously, structural and electrical characteristics were measured. For the manufacture of the AZO were vapor-deposited in the named order. It is well-known that post-annealing is an important method to improve crystal quality. For the annealing process, the dislocation nd other defects arise in the material and adsorption/decomposition occurs. The XRD patterns of the AZO films deposited with grey theory prediction design, annealed in a vacuum ambient(2.0{times}10-3Torr)at temperatures of 200, 300, 400 and 500?C for a period of 30min. The diffraction patterns of all the films show the AZO films had a hexagonal wurtzite structure with a preferential orientation along the c-axis perpendicular to the substrate surface. As can be seen, the (002)peak intensities of the AZO films became more intense and sharper when the annealing temperature increased. On the other hand, When the annealing temperature was 500?C the peak intensity decreased. The surface morphologies and surface toughness of films were examined by atomic force microscopy(AFM, XE-100, PSIA). Electrical resistivity, Gall mobility and carrier concentration were measured by Hall effect measuring system (HL5500PC, Accent optical Technology, USA). The optical absorption spectra of films in the ultraviolet-visibleinfrared( UV-Vis-IR) region were recorder by the UV spectrophotometer(U-3501, Hitachi, Japan). The resistivity, carrier concentration, and Hall mobility of ZnS deposited on glass substrate as a function of post-annealing.

진공 석영관에서 Selenization한 CuInSe₂ 박막 특성분석

양현훈(Yang, Hyeon-Hun),백수웅(Back, Su-Ung),김한울(Kim, Han-Wool),한창준(Han, Chang-Jun),나길주(Na, Kil-Ju),김영준(Kim, Young Jun),소순열(So, Soon-Youl),박계춘(Park, Gye-Choon),이진(Lee, Jin),정해덕(Chung, Hae-Deok) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

본 실험에서는 CuInSe₂ 3원물질을 화학량론적 조성비가 되도록 박막을 제조하기 위해 각 단위원소를 원자비에 맞춰 전자선가열 진공증착기를 사용하여 Cu, In, Se 순으로 증착하였다. 90?C이하의 온도에서 CuIn₂, In상이 주를 이루며, 100?C이상에서는 Cu_{11}In_9상이 나타나기 시작하고 In상이 증가하였다. 10^{-3}torr이상의 진공석영관에서 열처리와 동시에 Selenization을 통해 제작된 CuInSe₂박막은 열처리온도 250?C에서는 CuxSe, CuSe등의 2차상들이 나타나다가 450?C이상의 고온에서 CuInSe₂ 단일상을 형성하였다. 이로부터 진공중에서 반응을 시켰을 때, 더 낮은 온도에서 반응이 일어나고 열역학적으로 보다 안정한 소수의 화합물들이 쉽게 형성됨을 확인할 수 있었다. 특히 250?C에서는 Sphalerite 구조를 가지다가 350?C이상의 온도에서 Selenization하였을 때 Chalcopyrite 구조를 가졌다. 박막이 두꺼워지면서 결정립의 크기가 커지고 응력이 작아지는 특성을 보였다. 에너지 밴드갭은(E_g)은 Cu/In 성분비율이 클수록 작은값을 보였으며, 결절립크기가 증대되므로 결국 흡수계수가 낮아짐을 알 수 있다. 또한 두께가 증가할수록 전반적으로 흡수계수가 증가하였고 Cu/In의 성분비율이 0.97일 때 기초흡수파장은 1,169nm이고 에너지밴드갭은 1.06eV이었으며, 두께 1.5{mu}m이상일 때 전반적으로 양호한 상태의 p-type CuInSe₂박막을 제작하였다.

Characterization analysis of CuInS₂ absorber layer grown by heat treatment of low temperature

양현훈(Yang, Hyeon-Hun),백수웅(Back, Su-Ung),김한울(Kim, Han-Wool),한창준(Han, Chang-Jun),이석호(Lee, Suk-Ho),정운조(Jeong, Woon-Jo),박계춘(Park, Gye-Choon),이진(Lee, Jin),정해덕(Chung, Hae-Deok) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

CuInS₂ thin films were synthesized by sulfurization of Cu/In Stacked elemental layer deposited onto glass Substrates by vacuum furnace annealing at temperature 200[?C]. And structural and electrical properties were measured in order to certify optimum conditions for growth of the ternary compound semiconductor CuInS₂ thin films with non-stoichiometry composition. CuInS₂ thin film was well made at the heat treatment 200[?C] of SLG/Cu/In/S stacked elemental layer which was prepared by thermal evaporator, and chemical composition of the thin film was analyzed nearly as the proportion of 1 : 1 : 2. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM and hall measurement system. At the same time, carrier concentration, hall mobility and resistivity of the thin films was 9.10568{times}10^{17} [cm^{-3}], 312.502 [cm²/V{cdot}s] and 2.36{times}10^{-2} [{Omega}{cdot}cm], respectively.