K<SUB>2</SUB>CO<SUB>3</SUB> 첨가에 따른 H<SUB>2</SUB>S 제거용 무기계 흡착제의 흡착성능 영향에 관한 연구

장길남(Kil Nam Jang),송영상(Young Sang Song),홍지숙(Ji Sook Hong),유영우(Young-Woo You),황택성(Taek Sung Hwang) 한국청정기술학회 2017 청정기술 Vol.23 No.3

본 연구는 악취가스 물질(바이오가스의 불순물)의 하나인 H2S를 제거하기 위한 흡착제의 성능을 향상시키기 위해 수행하였다. 기본 담체로서 4가지 물질(Fe2O3, Ca(OH)2, 분말 활성탄, Al(OH)3)을 혼합 사용하여 pellet 형태의 흡착제를 제조하였다. 또한, 4가지 물질의 H2S 흡착에 미치는 영향을 평가한 결과, Fe2O3와 분말활성탄은 H2S 흡착성능이 각각 1.5, 2배로 증가하는 것으로 나타났으며 Ca(OH)2와 Al(OH)2는 H2S 흡착성능에는 영향이 없는 것으로 나타났다. 또한 4가지 물질을 기본혼합 담체로 한 후, 활성물질로 KI, KOH, K2CO3를 선정하여 각각 5 wt% 첨가한 후에 H2S 흡착성능을 시험한 결과 K2CO3를 첨가한 흡착제가 가장 성능이 우수한 것으로 나타났다. 또한 K2CO3를 5 ~ 30 wt%까지 변화시키면서 흡착성능을 확인한 결과, K2CO3 함량이 20 wt%까지는 함량과 비례하여 H2S 흡착성능이 증가하는 것을 확인할 수 있었으나 30 wt%에서는 H2S 흡착성능 급격히 떨어지는 것을 확인하였다. 또한 K2CO3 첨가 함량에 따른 H2S 흡착성능을 바탕으로 Thomas model을 이용하여 모델링을 실시한 결과에서도 K2CO3 함량이 20 wt%까지는 실험값과 모사값이 잘 일치하고 있음을 보여주었다. 이러한 결과들을 바탕으로, 본 연구에서 확인된 활성물질의 종류와 활성물질의 함량을 흡착제 제조에 이용한다면 H2S 흡착제의 흡착성능 개선뿐만 아니라 흡착제의 사용수명 증대를 기대할 수 있었다. The goal of this paper was to improve the performance of the adsorbent to remove H2S. Pellet type adsorbents were prepared by using four kinds of materials (Fe2O3, Ca(OH)2, Activated carbon, Al(OH)2) for use as a basic carrier. As the results of H2S adsorption tests, Fe2O3 and Activated Carbon improved the adsorption performance of H2S by 1.5 ~ 2 times, and Ca(OH)2 and Al(OH)2 showed no effect on H2S adsorption performance. Four basic materials were as carriers, and 5 wt% of KI, KOH and K2CO3 were added on the carriers, respectively. As the results of H2S adsorption tests, adsorbent containing K2CO3 showed the best performance. As a result of H2S adsorption test with varying K2CO3 content from 5 to 30 wt%, it was confirmed that adsorption performance was increased up to 20 wt% of K2CO3 and adsorption performance decreased to 30 wt%. The H2S adsorption performance was modeled by using Thomas model with varying K2CO3 contents and the results were used for the adsorption tower design. It was shown that the experimental values and the simulated values were in good agreement with the contents range of K2CO3 up to 20 wt%. Based on these results, it is expected that not only the adsorption performance of H2S adsorbent is improved but also life time of the adsorbent is increased.

H₂S 독성가스감지기가 필요한 정량적 공정설비 기준 및 비상시 안전을 위한 위치선정 방안에 대한 연구

최재영,권정환,Choi, Jae-Young,Kwon, Jung-Hwan 한국가스학회 2018 한국가스학회지 Vol.22 No.2

Design techniques for minimizing the damage caused by leakage of $H_2S$ gas, contained in natural gas and petroleum, have been widely studied abroad in chemical plants that purify and process natural gas and petroleum. However, there is no domestic engineering practice and regulation of $H_2S$. In accordance with the circumstances, this study proposes the quantitative criteria of process equipment to install $H_2S$ toxic gas detector as 500 ppm and explains the valid basis. The $H_2S$ gas dispersion radius up to IDLH 100 ppm is calculated by ALOHA under previous $H_2S$ gas leak accident scenario. The weather conditions of modeling include the conditions of Ulsan, Yeosu and Daesan, the three major petrochemical complexes in Korea. The long radius up to 100 ppm was derived in order of Ulsan, Daesan, Yeosu. For emergency safety the dispersion radius up to 100 ppm of the $H_2S$ gas obtained in this study should be extended to apply the additional $H_2S$ toxic gas detector, and local climate conditions should be considered. 천연가스 및 석유를 정제 및 가공하는 화공플랜트에서 원료에 함유된 황화수소($H_2S$)의 누출로 인한 피해를 최소화시키기 위한 설계 기법들이 세계적으로 널리 연구되어왔다. 그러나 국내에서는 화공플랜트에서 $H_2S$ 가스 피해 최소화를 위한 별도의 뚜렷한 설계 지침 및 규제가 없는 실정이다. 그러므로 본 연구는 $H_2S$ 독성가스감지기를 설치해야 할 공정설비의 $H_2S$ 가스 함량의 정량적 기준을 500 ppm으로 제시하고 타당한 근거를 설명하였다. 또한 ALOHA 프로그램을 사용하여 과거 $H_2S$ 가스 누출 사고를 재구성하여 IDLH 값인 100 ppm까지의 확산 반경을 산출하였다. 모델링의 기상 조건은 국내 3대 석유화학단지가 위치한 울산, 여수, 대산의 조건을 각각 적용하였으며, 울산, 대산, 여수 순서로 긴 반경이 도출되었다. 비상시 안전을 위해서 본 연구에서 얻은 $H_2S$ 가스의 100 ppm까지의 확산 반경을 고려한 추가적인 $H_2S$ 독성가스감지기가 설치되어야 하고, 이때는 반드시 지역별 기후조건이 고려되어야 할 것이다.

K2CO3 첨가에 따른 H2S 제거용 무기계 흡착제의 흡착성능 영향에 관한 연구

장길남,송영상,홍지숙,유영우,황택성 한국청정기술학회 2017 청정기술 Vol.24 No.3

The goal of this paper was to improve the performance of the adsorbent to remove H2S. Pellet type adsorbents were prepared by using four kinds of materials (Fe2O3, Ca(OH)2, Activated carbon, Al(OH)2) for use as a basic carrier. As the results of H2S adsorption tests, Fe2O3 and Activated Carbon improved the adsorption performance of H2S by 1.5 ~ 2 times, and Ca(OH)2 and Al(OH)2 showed no effect on H2S adsorption performance. Four basic materials were as carriers, and 5 wt% of KI, KOH and K2CO3 were added on the carriers, respectively. As the results of H2S adsorption tests, adsorbent containing K2CO3 showed thebest performance. As a result of H2S adsorption test with varying K2CO3 content from 5 to 30 wt%, it was confirmed that adsorption performance was increased up to 20 wt% of K2CO3 and adsorption performance decreased to 30 wt%. The H2S adsorption performance was modeled by using Thomas model with varying K2CO3 contents and the results were used for the adsorption tower design. It was shown that the experimental values and the simulated values were in good agreement with the contents range of K2CO3 up to 20 wt%. Based on these results, it is expected that not only the adsorption performance of H2S adsorbent is improved but also life time of the adsorbent is increased. 본 연구는 악취가스 물질(바이오가스의 불순물)의 하나인 H2S를 제거하기 위한 흡착제의 성능을 향상시키기 위해 수행하였다. 기본 담체로서 4가지 물질(Fe2O3, Ca(OH)2, 분말 활성탄, Al(OH)3)을 혼합 사용하여 pellet 형태의 흡착제를 제조하였다. 또한, 4가지 물질의 H2S 흡착에 미치는 영향을 평가한 결과, Fe2O3와 분말활성탄은 H2S 흡착성능이 각각 1.5, 2배로 증가하는 것으로 나타났으며 Ca(OH)2와 Al(OH)2는 H2S 흡착성능에는 영향이 없는 것으로 나타났다. 또한 4가지 물질을 기본혼합 담체로 한 후, 활성물질로 KI, KOH, K2CO3를 선정하여 각각 5 wt% 첨가한 후에 H2S 흡착성능을 시험한 결과 K2CO3를 첨가한 흡착제가 가장 성능이 우수한 것으로 나타났다. 또한 K2CO3를 5 ~ 30 wt%까지 변화시키면서 흡착성능을 확인한 결과, K2CO3 함량이 20 wt%까지는 함량과 비례하여 H2S 흡착성능이 증가하는 것을 확인할 수 있었으나 30 wt%에서는 H2S 흡착성능 급격히 떨어지는 것을 확인하였다. 또한 K2CO3 첨가 함량에 따른 H2S 흡착성능을 바탕으로 Thomas model을 이용하여모델링을 실시한 결과에서도 K2CO3 함량이 20 wt%까지는 실험값과 모사값이 잘 일치하고 있음을 보여주었다. 이러한 결과들을 바탕으로, 본 연구에서 확인된 활성물질의 종류와 활성물질의 함량을 흡착제 제조에 이용한다면 H2S 흡착제의 흡착성능 개선뿐만 아니라 흡착제의 사용수명 증대를 기대할 수 있었다.

Gadolinium-Doped CeO2 Gas Sensor for H2S Sensing

진창현,Sangwoo Kim,김동응,Ali Mirzaei,Jong Wook Roh,최선우,최명식 대한금속·재료학회 2023 대한금속·재료학회지 Vol.61 No.6

Dihydrogen sulfide (H2S) gas has a flammable nature and is one of the most toxic and dangerousgases. Even small concentrations can be fatal to humans. Herein, we investigated the H2S gas-sensingfeatures of commercial pristine cerium oxide (CeO2) and gadolinium (Gd)-doped CeO2 (GDC) nanoparticles. First, the sensing materials were well-characterized using various methods including X-ray photoelectronspectroscopy, transmission electron microscopy and X-ray diffraction to gain insight into their chemicalcomposition, morphology, phases, and crystallinity, respectively. In the next step, gas sensors were fabricatedusing a top electrode (Au/Ti) configuration. Preliminary H2S-gas-sensing studies revealed that GDC gas sensorhad a superior gas response to H2S gas than the pristine CeO2 gas sensor at 350°C. The responses of thepristine CeO2 gas sensor to 20 ppm H2S gas was 1.542, while the response of the GDC gas sensor to theaforementioned H2S concentration was 3.489. In addition, the GDC sensor exhibited good selectivity to H2Sgas among C2H5OH, C7H8 and NH3 gases. Also, we investigated the response of the sensor in up to 60%relative humidity. The enhanced response of the GDC gas sensor to H2S gas was mainly related to theformation of oxygen defects as a result of Gd-doping in CeO2. Also, good selectivity to H2S was related to thesensing temperature, the higher reactivity of H2S relative to other gases and the small bond energy of H-SH. This study demonstrates the promising ability of Gd-doping to enhance the H2S gas-sensing characteristicsof CeO2, which can be applied to other similar systems based on semiconducting metal oxides.

Fe₃S₄/Fe₇S₈-promoted degradation of phenol via heterogeneous, catalytic H₂O₂ scission mediated by S-modified surface Fe²⁺ species

Choe, Yun Jeong,Byun, Ji Young,Kim, Sang Hoon,Kim, Jongsik Elsevier 2018 Applied catalysis. B, Environmental Vol.233 No.-

<P><B>Abstract</B></P> <P>Enhancing OH productivity via heterogeneous, catalytic H<SUB>2</SUB>O<SUB>2</SUB> activation is a long-standing conundrum in H<SUB>2</SUB>O purification and thus requires the renovation of conventional reaction systems. The initial step in realizing advanced H<SUB>2</SUB>O<SUB>2</SUB> decomposition via heterogeneous catalytic manner is the exploration of the solid capable of efficiently cleaving OO bond inherent to H<SUB>2</SUB>O<SUB>2</SUB> and minimizing the loss of catalytic species during vigorous reaction dynamics. While using phenol as a model compound for recalcitrants, this paper highlights the use of Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> as a catalyst to enhance OH productivity and thus promote phenol degradation via electro-Fenton reaction over conventional Fe<SUB>2</SUB>O<SUB>3</SUB>, Fe<SUB>3</SUB>O<SUB>4</SUB>, and other sulfide analogue (FeS<SUB>2</SUB>). Materials’ characterizations and kinetic interpretation of reaction runs under controlled environments served to substantiate the benefits which were provided by Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> during the reaction. Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> incorporated greater amount of S-modified, surface-exposed Fe<SUP>2+</SUP> sites to cleave H<SUB>2</SUB>O<SUB>2</SUB> than FeS<SUB>2</SUB>. This improved catalytic consequence of Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> (i.e., phenol conversion and initial reaction rate), as also evidenced by control runs detailing H<SUB>2</SUB>O<SUB>2</SUB> decomposition in conjunction with <I>tert</I>-butyl alcohol-driven OH scavenging. Filtration control runs as well as recycle runs were also used to verify that Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> could heterogeneously catalyze H<SUB>2</SUB>O<SUB>2</SUB> scission under the mild, adequate reaction environments, which were realized by the use of low electrical powers and the catalyst immobilized on a cathode.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> with greater amount of surface Fe<SUP>2+</SUP> species to dissociate H<SUB>2</SUB>O<SUB>2</SUB> compared to FeS<SUB>2</SUB>. </LI> <LI> Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> with supported Fe<SUP>2+</SUP> sites to heterogeneously catalyze H<SUB>2</SUB>O<SUB>2</SUB> fragment. </LI> <LI> Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> with promoted catalytic H<SUB>2</SUB>O<SUB>2</SUB> scission ability compared to Fe<SUB>2</SUB>O<SUB>3</SUB>, Fe<SUB>3</SUB>O<SUB>4</SUB>, and FeS<SUB>2</SUB>. </LI> <LI> Fe<SUB>3</SUB>S<SUB>4</SUB>/Fe<SUB>7</SUB>S<SUB>8</SUB> with enhanced phenol degradation performance over other Fe-analogues. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Biocompatible silica nanoparticles conjugated with azidocoumarin for trace level detection and visualization of endogenous H₂S in PC3 cells

Rajalakshmi, Kanagaraj,Nam, Yun-Sik,Youg, Sumin,Selvaraj, Muthusamy,Lee, Kang-Bong Elsevier 2018 Sensors and actuators. B Chemical Vol.259 No.-

<P><B>Abstract</B></P> <P>The silica nanoparticles (SiO<SUB>2</SUB>NPs) conjugated with azidocoumarin (Cy-N<SUB>3</SUB>) was applied for the selective and sensitive H<SUB>2</SUB>S detection, even when H<SUB>2</SUB>S was present in 1000-fold excess of other bio thiols and ions. In the silica nanoprobes, azide in the Cy-N<SUB>3</SUB> group acted as the recognition element, and the probe was biocompatible. The nanoprobe displayed blue emission at 456 nm and excitation at 367 nm. After introducing H<SUB>2</SUB>S into the probe solution, the fluorescent intensity at 456 nm increased linearly as a function of H<SUB>2</SUB>S concentration (correlation coefficient, 0.9970), and the limit of detection was 6 nM. The enhanced fluorescent emission intensity was due to H<SUB>2</SUB>S-mediated reduction of the electron-withdrawing azide into electron-donating amine. The SiO<SUB>2</SUB>NPs@Cy-N<SUB>3</SUB> and its reaction products with H<SUB>2</SUB>S (SiO<SUB>2</SUB>NPs@Cy-NH<SUB>2</SUB>) were characterized by <SUP>1</SUP>H NMR and TEM. The probe also showed low cytotoxicity and could trace endogenous H<SUB>2</SUB>S in physiological pH. We therefore then successfully utilized it to detect H<SUB>2</SUB>S in living PC3 cells. The probe was also successfully employed for detection of H<SUB>2</SUB>S gas using Whatman papers coated with SiO<SUB>2</SUB>NPs@Cy-N<SUB>3</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biocompatible chemosensor for H<SUB>2</SUB>S detection was developed using silica nanoparticles. </LI> <LI> H<SUB>2</SUB>S detection was achieved even in 1000-fold excess of other interferents. </LI> <LI> The lowest LOD was 6 nM under physiological conditions. </LI> <LI> The probe was successfully applied for H<SUB>2</SUB>S detection in live PC3 cells. </LI> <LI> The paper strip probe coated with silica nanoparticles successfully detected H<SUB>2</SUB>S. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

H₂O/N₂/H₂S 혼합가스 분위기 900℃에서 캐스타블 내화물의 부식

신민,윤종원,김창삼,Shin, Min,Yoon, Jong-Won,Kim, Chang-Sam 한국결정성장학회 2017 한국결정성장학회지 Vol.27 No.2

저급탄을 가스화하는 반응기에 사용되는 내화물은 고온에서 부식성이 강한 $H_2S$ 가스에 노출되며, 경도나 내마모성과 같은 기계적 특성이 가스에 노출되는 시간이 길어짐에 따라서 떨어진다. 그러나 $H_2S$ 가스에 의한 내화물의 기계적 특성 약화 원인이 아직 잘 알려져 있지 않다. 본 실험에서는 내화도가 다른 두 종류의 케스터블 내화물을 $H_2S$ 농도가 높은 $H_2O/N_2/H_2S$ 혼합가스에 100시간 동안 $900^{\circ}C$에서 노출시키고, 미세구조, 결정상과 내마모 특성 변화를 비교하였다. 혼합가스에 노출되면서 내화물 시편의 무게는 감소하였다. 노출 후 기공률은 감소하고, 내마모 특성은 현저하게 떨어졌다. 부식에 의해서 내화물을 구성하는 상에 변화가 일어났는데, $CaAl_2O_4$와 일부의 $SiO_2$는 사라지고 $CaSO_4{\cdot}2H_2OS$와 $Al_2Si_2O_5(OH)_4$ 상이 나타났다. 내화물의 내마모 특성이 $H_2S$ 가스에 노출된 후에 감소하는 주 원인은 캐스터블 내화물에서 결합제 역할을 하는 $CaAl_2O_4$가 사라지고 기계적 특성이 나쁜 $CaSO_4{\cdot}2H_2OS$가 생성되기 때문인 것으로 생각되었다. Refractories used in low-rank coal gasification reactors are usually exposed in a highly corrosive $H_2S$ gas at less than $1000^{\circ}C$, and their mechanical properties such as erosion resistance and fracture strength decline with the exposure time. However, the cause of the degradation of the mechanical properties has little reported yet. In this paper, two kinds of castable refractories with different refractoriness had been exposed in a $H_2O/N_2/H_2S$ mixed gas with high $H_2S$ content for 100 hours at $900^{\circ}C$, and the changes of microstructure, crystalline phases and erosion resistance were compared before and after the corrosion test. The weight of the refractories decreases due to the elution of silica in the specimens after the corrosion test. The capillary porosities of the samples are reduced, but the erosion resistance of the samples is fatally weakened after the corrosion test. There also are changes in constituent phases; dmitryivanovite ($CaAl_2O_4$) and amorphous silica ($SiO_2$) disappear, and gypsum ($CaSO_4{\cdot}2H_2OS$) and kaolinite ($Al_2Si_2O_5(OH)_4$) newly appear after the corrosion test. It is obvious that the phase change from dmitryivanovite that works as a binding agent in the castable refractory to gypsum is the main reason of the degradation of the erosion resistance, because the mechanical properties of gypsum are much poorer than those of dmitryivanovite.

Effect of pre-annealing on the phase formation and efficiency of CZTS solar cell prepared by sulfurization of Zn/(Cu,Sn) precursor with H₂S gas

Lee, J.H.,Choi, H.J.,Kim, W.M.,Jeong, J.H.,Park, J.K. Association for Applied Solar Energy ; Elsevier Sc 2016 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.136 No.-

The effect of pre-annealing on the phase formation behavior and efficiency of CZTS thin film solar cell prepared by sulfurization of sputtered Zn/(Cu,Sn) metal precursor with H<SUB>2</SUB>S gas was investigated. Precursor with stacking structure of Zn/(Cu,Sn) was deposited by sputtering of Cu, Zn, and Sn metal targets. The depth profile of metal elements and cell efficiency of the sulfurized CZTS films with H<SUB>2</SUB>S were observed to be critically dependent on the pre-annealing conditions. For the CZTS film prepared by sulfurization in N<SUB>2</SUB>-5vol.% H<SUB>2</SUB>S at 550<SUP>o</SUP>C after pre-annealing at 350<SUP>o</SUP>C in Ar, segregation of SnS phase at the surface region was observed to be pronounced. When the pre-annealing was performed at 350<SUP>o</SUP>C in N<SUB>2</SUB>-5vol.% H<SUB>2</SUB>S, however, uniform depth profile of metal elements with a small amount of CuS phase was observed. The CuS phase was disappeared with increase in the pre-annealing temperature in N<SUB>2</SUB>-5vol.% H<SUB>2</SUB>S. The phase formation behavior influenced by pre-annealing condition was observed to affect solar cell performance of the CZTS thin film synthesized at 550<SUP>o</SUP>C in N<SUB>2</SUB>-5vol.% H<SUB>2</SUB>S. In contrast to the CZTS thin film prepared with pre-annealing at 350<SUP>o</SUP>C in Ar showing bad efficiency (~0.93%), the CZTS solar cells fabricated with pre-annealing at 450<SUP>o</SUP>C in H<SUB>2</SUB>S shows higher efficiency of 3.04%. By the optimization of Zn layer thickness, solar cell efficiency of 4.40% was obtained in the CZTS thin film prepared with pre-annealing at 450<SUP>o</SUP>C in N<SUB>2</SUB>-5vol.% H<SUB>2</SUB>S. This phenomenon was due to the change in the secondary phase formation behavior during sulfurization of the Zn/(Cu,Sn) metal precursor with various pre-annealing conditions.

Removal of hydrogen sulfide from a steam-hydrogasifier product gas by zinc oxide sorbent: Effect of non-steam gas components

김기석,Nokuk Park 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.6

Removal of H2S from a steam-hydrogasifier product gas was studied at 636 K and 1 atm using a commercially available zinc oxide sorbent in a packed-bed reactor. A mixture gas containing 22% CH4,18.7% H2, 8.8% CO and 5.5% CO2 (non-steam components subtotaling to 55%) balanced with steam was used to simulate the steam-hydrogasifier product gas. Sorbent particles of 150–250 mm size were used to eliminate the effect of intraparticle mass transfer limitation. Experiments were conducted to monitor H2S breakthrough of reactor effluent stream for operation parameters such as space velocity and inlet H2S concentration. With space velocity varied from 6000 to 8000 to 12,000 h1 for inlet H2S concentration in the range of 100–800 ppmv, sulfur capture capacity of the sorbent (Scap) for 2 ppmv H2S breakthrough did not change notably, indicating that, for each inlet H2S concentration tested, sorbent utilization for sulfur removal was not affected by the space velocity. Meanwhile, for each space velocity tested, Scap increased monotonically as the inlet H2S concentration increased from 100 to 500 to 800 ppmv,which is opposite to the result observed for the mixture gas devoid of CH4, H2, CO and CO2. As the overall content of these non-steam components of the simulation gas was halved for each inlet H2S concentration tested at 8000 h1 space velocity, Scap for non-steam gas components of 27.5% content corresponded approximately to themedian value of those for the non-steam gas components of 55% and 0% content, suggestive of linear dependency of Scap upon the content of the non-steam components for the inlet H2S concentration tested. 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Interface sulfur passivation using H₂S annealing for atomic-layer-deposited Al₂O₃ films on an ultrathin-body In_0.53Ga_0.47As-on-insulator

Jin, H.S.,Cho, Y.J.,Lee, S.M.,Kim, D.H.,Kim, D.W.,Lee, D.,Park, J.B.,Won, J.Y.,Lee, M.J.,Cho, S.H.,Hwang, C.S.,Park, T.J. New York] ; North-Holland 2014 APPLIED SURFACE SCIENCE - Vol.315 No.-

Atomic-layer-deposited Al<SUB>2</SUB>O<SUB>3</SUB> films were grown on ultrathin-body In<SUB>0.53</SUB>Ga<SUB>0.47</SUB>As substrates for III-V compound-semiconductor-based devices. Interface sulfur (S) passivation was performed with wet processing using ammonium sulfide ((NH<SUB>4</SUB>)<SUB>2</SUB>S) solution, and dry processing using post-deposition annealing (PDA) under a H<SUB>2</SUB>S atmosphere. The PDA under the H<SUB>2</SUB>S atmosphere resulted in a lower S concentration at the interface and a thicker interfacial layer than the case with (NH<SUB>4</SUB>)<SUB>2</SUB>S wet-treatment. The electrical properties of the device, including the interface property estimated through frequency dispersion in capacitance, were better for (NH<SUB>4</SUB>)<SUB>2</SUB>S wet-treatment than the PDA under a H<SUB>2</SUB>S atmosphere. They might be improved, however, by optimizing the process conditions of PDA. The PDA under a H<SUB>2</SUB>S atmosphere following (NH<SUB>4</SUB>)<SUB>2</SUB>S wet-treatment resulted in an increased S concentration at the interface, which improved the electrical properties of the devices.