Endoscopy and Imaging Modalities/Basic Science of Gastrointestinal Disorders/Miscellaneous : Changing Pattern Of Digestive And Liver Disease In Korea, 1990-2006 Year; A Single Center Study

( Jung Hyun Kwon ),( Sang Woo Kim ),( In Sik Chung ),( Myung Gyu Choi ),( Kwan Woo Nam ),( Jung Pil Suh ),( Jae Hyuck Chang ),( Won Haing Hur ),( Yu Kyung Cho ),( Jae Myung Park ),( In Seok Lee ) 대한소화기학회 2007 SIDDS Vol.9 No.-

Background/Aims: Westernization in many Asian countries have changed lifestyles and diets, so once rare diseases have now become prevalent. The aim of this study is to investigate the changing pattern of digestive and liver disease in Korea, from 1990 to 2006. Methods: We extracted data specific gastrointestina (GI) disease based on the International Classification of Diseases code from the in-patients records at the Kangnam St. Mary`s Hospital in 1990, 1996 and 2006. This hospital is a tertiary-care hospital in Seoul, Korea, which has a capacity of 800 beds. Results: The admission rate for GI disease increased between 1990 and 2006. Overall in-patients were 1,623 persons in 1990, 2,368 persons in 1996 and 4,166 persons in 2006. The mean age of in-patients increased as time went by. A stomach cancer was the most common diagnosis during all periods, but its prevalence has decreased. Colon cancer ranked the 7th in 1990, but markedly increased and now ranks the second. The third was a hepatocellular carcinoma. The bile duct and gallbladder cancer, pancreas and esophageal cancer ranking followed with little interval change. In cases of cancer patients, a regular admission dramatically increased for chemotherapy. The number of patients admitted with pre-malignant neoplasm of stomach and colon increased remarkably with the development of endoscopy. The liver transplant, inflammatory bowel discase, and reflux esophagitis emerged form mid-1990s with greater frequencies, yet much below the levels found in the West. The admission rate for peptic ulcer, especially ulcer bleeding remained relatively stable, despite a decreased rate for ulcer perforation. Liver cirrhosis, hepatitis, cholelithiasis with cholecystitis-cholangitis, appendicitis, hemorrhoid and gastritis all decreased. Conclusions: The stomach cancer is the leading cause of admission, despite a recent decline. Colon cancer showed a marked rise. The liver transplant, inflammatory bowel disease and reflux esophagitis were new diagnosis with an increased tendency.

Adult invasive pneumococcal disease in the Republic of Korea: Risk medical conditions and mortality stratified by age group

Kim, Jong Hun,Baik, Seung Hee,Chun, Byung Chul,Song, Joon Young,Bae, In-Gyu,Kim, Hyo Youl,Kim, Dong-Min,Choi, Young Hwa,Choi, Won Suk,Jo, Yu Mi,Kwon, Hyun Hee,Jeong, Hye Won,Kim, Yeon-Sook,Kim, Jeong Elsevier 2018 INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES Vol.74 No.-

<P><B>Abstract</B></P> <P><B>Objectives</B></P> <P>This study aimed to characterize the risk factors for mortality in adult patients with invasive pneumococcal disease (IPD) stratified by age groups, after implementation of the national immunization program of 23-valent polysaccharide vaccine (PPSV23) for those aged ≥65 years in the Republic of Korea (ROK).</P> <P><B>Methods</B></P> <P>Clinical data and pneumococcal isolates from adult patients with IPD (≥18 years of age) were collected prospectively from 20 hospitals through the nationwide surveillance program from March 2013 to October 2015.</P> <P><B>Results</B></P> <P>A total of 319 patients with IPD were enrolled. Median age was 69 years. Overall in-hospital mortality was 34.2%: 17.1% in those aged 18–49 years, 23.7% in those aged 50–64 years, 33.0% in those aged 65–74 years, and 51.0% in those aged ≥75 years (<I>p<</I> 0.001). In particular, early death within 7days of hospitalization accounted for 60.6% (66/109). While old age (≥65 years), higher Pitt bacteremia score (≥4), and bacteremic pneumonia were independently associated with IPD mortality in all age groups, an additional mortality risk factor of immunocompromised status was identified for patients aged 50–64 years. PPSV23 serotypes accounted for 64.4% (122/189) of the pneumococcal isolates serotyped.</P> <P><B>Conclusions</B></P> <P>This study suggests that vaccine-type IPD continues to place a substantial burden on older adults in the ROK, necessitating an effective vaccination strategy for those at higher risk.</P> <P><B>Highlights</B></P> <P> <UL> <LI> National immunization of the elderly with the 23-valent polysaccharide vaccine (PPSV23) was implemented in Korea in 2013. </LI> <LI> Overall in-hospital mortality was 34.2% for adult invasive pneumococcal disease (IPD) and 51.0% for patients ≥75 years of age. </LI> <LI> Mortality risks were older age, higher bacteremia score, and immunocompromised status. </LI> <LI> An effective vaccination strategy for those at higher risk of IPD is needed. </LI> </UL> </P>

HPLC를 이용한 지역 농산물의 비타민 B₆ 함량 분석

최소라 ( So-ra Choi ),송은주 ( Eun-ju Song ),송영은 ( Young-eun Song ),최민경 ( Min-kyung Choi ),한현아 ( Hyun-ah Han ),이인석 ( In-sok Lee ),신소희 ( So-hee Shin ),이기권 ( Ki-kwon Lee ),최용민 ( Young-min Choi ),김행란 ( Haeng-r 한국식품영양학회 2017 韓國食品營養學會誌 Vol.30 No.4

Contents of water soluble vitamin B6 in a total of 62 agricultural products cultivated in local areas in Korea were analyzed by high performance liquid chromatography with fluorescence detector (HPLC/FLD). To verify the method of vitamin B6 analysis, a quality control chart was formulated with in-house control using a mixture of broccoli and shiitake mushrooms. Among cereals, high content of vitamin B6 measured 234.3~260.3 μg/100 g in dried mung bean and soybean. Vitamin B6 content of non-glutinous and glutinous black rice measured 105.0 μg/100 g and 129.7 μg/100 g, respectively. In vegetables, high content of vitamin B6 were measured in passion fruit (104.3 μg/100 g), gat (55.7~84.3 μg/100 g), gomchwi (31.3~88.0 μg/100 g) and garlic (72.7~98.3 μg/100 g). Among fruits, gold kiwi 'Zespri' and green kiwi 'Hayward' revealed high vitamin B6 content of 116.3 μg/100 g and 78.7 μg/100 g, respectively. In persimmons, daebongsi had high vitamin B6 content (36.0~72.7 μg/100 g) than bansi and sweet persimmon. Vitamin B₆ content in dried jujube and persimmon increased more than 86.7 μg/100 g compared to fresh materials. Among specialty crops, green tea powder (64.7~251.0 μg/100 g) and sansuyu (172.3 μg/100 g) revealed high content. Of mushrooms, vitamin B6 content of Sparassis crispa (139.3 μg/100 g) was the highest. Vitamin B6 content information of agricultural products in local areas in Korea collected from this experiment will be used as valuable preliminary data for grasp national nutritional status.

[18F]FDG PET을 이용한 강박증 환자에서 뇌 포도당 대사의 이상에 관한 연구

권준수,이동우,이재성,최정임,이동수,정준기,조맹제,이명철,류인균 대한신경정신의학회 2000 신경정신의학 Vol.39 No.2

연구목적: 강박증에 대한 기능적 뇌영상 연구들에서 강박증 환자들의 안와전두엽과 미상핵의 대사율 증가 소견이 비교적 일과되게 발표되어 왔으며, 전두-피질하 회로의 이상이라는 이론이 수립되기도 하였다. 그러나 기존의 연구들은 강박증의 유병기간에 따른 구분없이 시행된 연구였고, 영상분석 방법에 있어서도 관심영역 방법을 이용했다는 한계를 지니고 있다. 본 연구의 목적은 첫째, 강박증의 유병기간에 따라 환자군을 구분하여 PET 영상소견을 분석함으로써 유병 기간에 따른 차이가 있는지를 조사하였으며, 둘째, 강바증 환자의 포도당 양전자방출 단층촬영(18-Fluor-deoxyglucose Positron Emission Tomography : FDG-PET) 영상분석에 통계적 매개변수 지도법(Statistical Parametric Mapping : SPM)을 이용함으로써 강박증의 병인기전 및 강박증상과 뇌기능 간의 관계를 명확히 규명하고자 하였다. 방법: 구조적 면담도구(Structured clinical interview for DSM-IV : SCID-IV)를 적용하여 진단된 12명의 강박증 환자들과 10명의 정상 대조군에 대해 FDG-PET을 촬영하여 SPM으로 분석하였다. PET 촬영 전 적어도 4주 동안에는 약물복용을 하지 않은 상태였다. 결과: 1) 환자군과 대조군의 비교 : 강박증 환자군은 대조군에 비해 양측 두정 영역의 대사율이 유의하게 감소되어 있었으며(P<0.01). 대사증가를 보인 영역은 없었다. 강박증의 유병기간이 10년 이상인 만성강박증 환자 4명은 양측 안와전두엽에서 유의한 대사증가 소견을 보였으며(P<0.01), 양측 두정영역에서 유의한 대사감소 소견을 보였다 (P<0.01), 유병기간이 10년 이하인 환자에서는 전체 환자군의 분석에서와 마찬가지로 대조군에 비해 유의한 대사증가 소견을 보인 영역은 없었으며, 양측 두정엽 부위에서 유 의한 대사 감소 소견을 보였다.(P<0.01). 2) 강박증상의 심각도와의 상관관계 분석 : 우측 두정엽의 대사율은 강박장애 척도 점수와 유의한 음의 상관관계를 보였으며(p<0.01), 양측 시상 영역의 대사율은 예일-브라운 강박장애 척도의 강박장애척도 점수와 유의한 양의 상관관계(p<0.01)를 보였다. 결론: 본 연구는 결과는 기존의 연구들에서 보고된 안와전두엽의 대사 증가 소견이 강박증의 만성화로 인해 나타나는 2차적 장애이며, 두정엽의 대사 저하가 보다 1차적인 장애일 가능성을 시사한다. Baxter가 수립한 전두-피질하 회로 이론은 두정엽의 이상을 포함하는 전두-두정엽 복합체 이론으로 확장되어야 할 것이다. Objectives: Functional imaging studies on obsessive-compulsive disorder(OCD) subjects have repeatedly reported increased metabolism in orbitofrontal lobes and caudate nucleus, resulting in the "frontal-subcortical" circuit abnormality theory. Limitations of the previous studies to date include little consideration for the duration of illness, and the use of regions of interest methods, as an image analysis method. Our study objectives are 1) to include the duration of illness as an important study variable, and 2) to use Statistical Parametric Mapping(SPM) method in order to tap relations between the brain function and the psychopathology and symptoms of OCD. Methods: The [18] fluorodeoxyglucose positron emission tomography(FDG-PET) scans of OCD subjects and normal comparison subjects, as diagnosed by the Structured Clinical Interview for DSM-IV(SCID-IV), were analyzed using SPM. Results: 1) Comparison of OCD and control groups : OCD subjects had significantly decreased metabolism in both parietal lobes and didn't have any areas of increased metabolism in comparison to comparison subjects(p.<0.01). four OCD subjects with the illness duration of 10 years or longer, had significantly increased metabolism in both orbitofrontal lobes<p<0.01). OCD subjects whose illness duration is shorter than 10 years didn't have any areas of increased metabolism and had significantly decreased parietal lobe metabolism, as in the analyses of all subjects(p<0.01). 2) Correlation analysis between areas and symptom severity : Metabolism of both thalamic sreas showed significant positive correlation with Yale-Brown Obsessive-Compulsive Scale(Y-BOCS) scores(p<0.01). Metabolism of right parietal area showed significant negative corre lation with Y-BOCS scores(p<0.01). Conclusions: The current findings suggest that the increased metabolism in orbitofrontal lobe, previously rported, may be a secondary phenomenon due to the extended illness dur- ation and that decreased metabolism in the parietal lobes are primary abnormality in OCD subjects. Thus Baxter's fronto-subcortical circuit theory should be extended into "fronto-pari-etal" complex theory, which includes the parietal lobes.

Yield of Rice Affected by Meteorological Elements in Yeosu Area of Korea

Kwon,Byung-Sun,Choi,Seong-Kyu,Shin,Jeong-Sik,Shin,Jong-Sup,Shin,Dong-Young,Hyun,Kyu-Hwan,Kuk,Yong-In,Park,Hee-Jin 한국자원식물학회 2003 Plant Resources Vol.6 No.2

This study was conducted to investigate the relationships between yearly variations of meteorological elements and yearly variations of productivity in rice. In addition, correlation coefficients among yield and yield components were used to find out the relationships between meteorological elements and productivity. Yearly variation of the mean air temperature in May was large with coefficients of variation(C.V.) of 25.0%, but the variation of the duration of sunshine in May were relative small. No. of panicles per hill and 1,000 grains wt. of brown rice were great with C.V. of 21.1, 19.7%, respectively, brown rice yield show more or less C.V. of 5.5% and milled rice show still less variation. Correlation coefficients between temperatures in period of cultivation from May and yield were positive correlations. Correlation Coefficients between precipitation in period of cultivation from Sep. to Oct. and yield are positive correlations. Correlation coefficients amount the panicle length, no. of panicles, no. of spikelets, ratio of ripened grains, 1,000 grains wt. of brown rice, milled rice yield, brown rice yield and milled rice yield were positively significant at the level of 1 %, respectively.

Relationship between Meteorological Elements and Yield of Hot Pepper in Yeosu Area of Korea

Kwon,Byung-Sun,Choi,Seong-Kyu,Shin,Jeong-Sik,Shin,Jong-Sup,Shin,Dong-Young,Hwan,Kyu-Hyun,Kim,Hak-Jin,Kuk,Yong-In,Choi,Kyong-Ju 한국자원식물학회 2003 Plant Resources Vol.6 No.1

This study was conducted to investigate the relationships between yearly variations of meteorological elements and yearly variations of productivity in hot pepper. In addition, correlation coefficients among the yields and yield components were used to find out the relationships between meteorological elements and productivity. Yearly variation of the mean air temperature in May and July showed large with coefficients of variation(C.V.) of 25.0,8.9%, respectively, but the variation of the duration of sunshine in May were relative small. Yield and plant height was greatly with C.V. of 7.14,11.6%, respectively, diameter of fruit showed more or less C.V. of 2.28% and length of fruit showed less variation. Correlation coefficients between maximum temperature in period of cultivation from May and yield are positively significant at the level of 1 %. Correlation Coefficients between precipitation in period of cultivation from May to August and yield are negative significant at the level of 5 and 1 %, respectively. Correlation coefficients amount the plant height, length of fruit, diameter of fruit per plant, and seed yield were positively significant at the level of 1 %, respectively.

Incidence of Adult In-Hospital Cardiac Arrest Using National Representative Patient Sample in Korea

Yuri Choi,In Ho Kwon,정진우,정준영,노영훈 대한의료정보학회 2016 Healthcare Informatics Research Vol.22 No.4

Objectives: This study analyzed the incidence and characteristics of in-hospital cardiac arrest (IHCA) in Korea based on a sample group of patients that is representative of the population. Methods: The incidence of IHCA in adults was extracted from HIRA-NIS-2009, a sample of all patients using medical services in Korea. IHCA patients were analyzed according to gender, age, type of medical institute, and classification under the 6th revision of the Korean Standard Classification of Diseases (KCD-6). In addition, to assess the differences arising from the size of medical institutes, the IHCA incidence was analyzed in relation to the number of inpatient beds. Results: Based on the sample data, the total incidence of IHCA in Korea was found to be 2.46 per 1,000 admissions (95% confidence interval [CI], 2.37–2.55). A higher incidence was found among men at 3.18 (95% CI, 3.03–3.33), compared to women at 1.84 (95% CI, 1.74–1.94). The incidence of IHCA was also higher in hospitals that had more than 600 inpatients beds at 5.40 (95% CI, 5.16–5.66) in comparison to those that had less than 600 inpatients beds at 4.09 (95% CI, 3.76–4.36) (p < 0.001). By primary disease, the incidence was the highest for infectious diseases. Conclusions: We demonstrated that the IHCA incidence based on gender, age, diagnostic group, and number of beds could be analyzed using the insurance claim data from a national representative sample.

氏族마을의 儒敎文化景觀 特性에 관한 연구 : 상주시 우산리를 사례로 in the Case of Usan Village in Sangju City

백인권,최기수 한국정원학회 2002 한국전통조경학회지 Vol.20 No.3

This study basically assumes that housing form is influenced by social/cultural backgrounds rather than natural circumstances. The most significant characteristic in villages, originated in Chosun dynasty, is that village people are linked with lineage. With this point of view, I focused on Usan-ri Sangju-si, Gyeongsangbuk-do, where famous Song Confucianism scholar Jung, Gyungse (鄭經世 , with the pen name of Ubok. 1563-1633)'s family had settled down. The purpose of the study is to find out both the general and specific characteristics of physical structure and cultural landscape in this lineage village, based on its planning and development process of the village. For the study, I focused on the gentry's personal design ideas as well as Song Confucianism's influence on buildings of the village. Sang-Usan village had been transformed since Ubok has lived in Usan village; cultural place(修己空間) →residential place(居住空間)→ceremonial place(儀禮空間). The pavilion(聽癎亭) has a simple structure without a kitchen, which means Ubok used the house for a limited purpose (as a studying and mental training), not for living. After Usan area was granted by Yeongjo(英祖) as a Royal gift, the descendants moved to Usan for dwelling and took care of it as a special place. There is two things that need to be focused for planning a traditional village in Korea: finding a place for mental training and/or studying and a vantage place for living. The residential area was relatively small. The characteristics of physical formation of the village had been changed. When Ubok had settled down in the village for the first time, the major reason of locating a house was finding a place for the cultivation of the mind. However, when Jung, Joowon (鄭胄源, 1686-1756) moved into the Usan village for residential purpose, take a farm near by Usan area. Ubok's absolute sprit and power is easily found in the Usan-ri area. for example, most of Confucianism facilities - such as carved letters on a stone(刻宇), Usan-Seowon(愚山書院), and the household shrine(家廟祠堂) - are placed in Sang-Usan(上愚山) village and other residential functions are placed in Ha-Usan(下愚山) village.

금속제 기구 및 용기포장의 유해물질에 관한 조사 연구 : 금속제 주방 기구에서 유해중금속 용출에 관한 연구 Study on Migration of Trace Elements from Metallic Kitchenwares

이광호,권기성,곽인신,전대훈,최병희,유승석,김성욱,이선희 식품의약품안전청 1998 식품의약품안전청 연보 Vol.2 No.-

구이웅즉불판, 스데"1크용 불판, 전골그릇. 솥, 프라이괜, 갬비, 주전자, 밥그릇 및 석쇠 둥 주방용 기구에 사웅되는 황동(3'3총)· 묵쇠 (17종), 알루미늄(10종), 청동(2종), 구리 (2종), 스테인레스(2종) 둥의 금속제에서 Pb, Cd, Ct Zn, Sn등 유괘 중금속의 용출과 기작에 대하여 연구하였다. 촹동을 대표금속으로 선정하여 용출 온도(30, 60, 80,95'c), PH(2.5, 4.3, 6.0, 7.0) 및 시간(30, 90, 180, 3:60븐)에 딱른 금속 용출량 조사에서 온도 및 P 변화체 딱른 시험결과, 95'C, pH 2.5인 조건에서 용출이 가장 많았던 반면, 용출 시간별 시험에서는 180분 이후까지 Pb가 용출된 후 편형 상태를 유지하였다. 위의 실험 결과로 미루어 현행 식품공전 시험법인 30분 조건에 대한 추후 재검토 연구가 필요하다고 잔단되며, 납이 용출되는 기작은 SEM을 통하띨 확인항 수 있었다. 황동의 경우, 재질줄의 Pb 항량곽용 출량과의 관계를 규명하기 위해 Pb 함략별 10종(0, 0.02, 0.09, 0.1, 0.2, 0.5, 0-9, 1.7, 5.4, 9.2%)의 시껼를 제작하여 4% 초산, 95'C, 30분에서 시험한 결과, 용출규격인 중금속이 1.Oppm(납으로서) 이하가 되기 위해서는 재질중 허용 Pb 함량은 0.2% 이하가 되어야 했다. 시중에 운통중인 각 재질별 금속제 기구에서 용출되는 유해중금속의 실태를 파악한결과, 황동제의 경우 주로 주물제품의 구이용 불판(양식 스테이크용 포함)으로 20종중 17종인 식풍 공전의 기준 ·규격인 1.OPPm이상의 Pb가 검출되어 85%의 련적합율을 뽀였다. Pb 용출 함량별 분포를 보면 1~10ppin이 15%, 20~100ppmo1 30%, 100~200ppmo1 20%, foo~300ppmol 10%, 300~400ppmo1 5%, 400~500ppr1 이 5%로 10~100ppm 사이의 용출량을 나타내는 제품이 가장 많이 유통되는 것으로 확인 되었다. 그외 Cu7l 0.37~77.85ppm, Zinc가 2.88~221.Oeppm, Fe이 미량 용출되었으며 Cd는 검출되지 않았다. 무꼭는 요즘 구이용 불판으로 사용되고 있는 솥뚜껑r 스테이크용 불판, 솥, 전골냄티, 프라이팬 등을 대상 겋체로 하였다. Fe이 0.S2~5,058 ppin, Cu, Zn 및 Pb등이 미량 검출 되었으며 Sn, Cd은 용출되지 않아 기준 ·규격에 적합한 것으로 판단.되었다. 알루디늄제는 램비 및 주전짜를 대상 검체로 하였는데 Cu, Zn, Sn, 및 Pb 등이 식품공전의 기준 · 규격의 IPPU내로 미량 검출되엇으며 Cd은 검출되지 않아 역시 기준·규격에 적합하다는 걸론을 얻었다. The migration of trace elements, Pb, Cd, Cu, Zn and Sn from metallie food-contactutensiles was investigated. All samples used in this work were grills, cooking pots, kettles, frying pansand bowls made of brass(20 samples), iron(17 samples) , aluminium(10 samples), copper(2 samples),bronze(2 samples) or stainless(2 samples). The migration of metats from brasses was affected by the iai-gration temperature(30, 60, 80 and 95'c ), the simulant pH (2.5, 4.3, 6.0 and 7.0) and the migration tirae(30,90, 180 and 360mia.). T,he amount of Pb migrati,oB was maximum at 95'c with pH 2.5. This study in-dicated that it could be required to reexamine the m igration time as 30 minutes suggested by the KoreaFood Code because the equilibrium of Pb migration was reached at 180 minutes. The mechanism of Pbmigration was investigated with Scanning Electron :Microscope(SEM) and Electron Probe Micro Analya-er(EPMA ). To correlate the relations between the m igration and the content of Pb in brass samples, tinbrass samples having known eontent of Pb(the quaritities of Fb in brass ; 0, 0.02, 0.09, 0,3,0.2, 0.5,0.9,1.4, 5.4 and 9.2% (w/w) ) were tested in the following conditions,4% acetic acid,95·C and 30 minutes. Theresult re?i?seBts that content of Pb in brass samples must be below 0.2% (w/w) to satis(y the 1.0 ppm(as Pb), of forea Food Code. The study was also coBlducted to estimate the migration of harmful metalsin metallic kitchenware made of brass, iron, alumiBium, copper, bronze and stainless. In the case ofbrass samples, the migration of Pb exceeded the 1.0 ppm in 17 among 20 samples with 85% rejectionrate. The pattern of the distribution for Pb migratioB was as followed; 15% : 1~10ppn1; 30% : fO~100ppm; 20% : 100~200ppm; 10% : 200~300ppm, 5% : 300~400ppm; 5% : 400~500ppm, respectivelr,while the content of otller metals detected as Cu 0.3,7~77.85ppm, Zn 2.88~221.Ooppm, Fe trace. Variousiron kitchenwares including sTilts, cooking pots ancl frying pans were also tested. The migration of themetals showed the following result, Fe . 0.52~s.07 ppm; Cu, Zn, Pb : trace; Sn. Cd : not detected.respectively. Aluminium kitchenwares like kettles were tested. There was no significant migration of trace metals, Cu, Zn, Sn, Fe and Pb, meanwhile the migration of Cd in samples made of the aluminium products could not be detected. The results demonstrated that iron and aluminium kitchenwares were suitable for Korea Food Code, however, brass products could provide harmful effect on human health.

Transfer of ultrathin molybdenum disulfide and transparent nanomesh electrode onto silicon for efficient heterojunction solar cells

Kang, Sung Bun,Kwon, Ki Chang,Choi, Kyoung Soon,Lee, Rochelle,Hong, Kootak,Suh, Jun Min,Im, Min Ji,Sanger, Amit,Choi, In Young,Kim, Soo Young,Shin, Jae Cheol,Jang, Ho Won,Choi, Kyoung Jin Elsevier 2018 Nano energy Vol.50 No.-

<P><B>Abstract</B></P> <P>Two-dimensional transition-metal dichalcogenides (TMDCs) are very promising for photovoltaic (PV) applications due to their excellent light absorption properties and appropriate bandgap energy, Although multifunctional applications of TMDCs in photovoltaic devices have been achieved, the photovoltaic conversion efficiency under 1 sun is still very low with small active area because of their inexpedient high sheet resistance and limitation of synthesis techniques. In this study, we demonstrate uniform synthesis of 4-in. wafer-scale MoS<SUB>2</SUB> thin films by thermal decomposition of solution precursors. The solar cells are fabricated by transferring n-MoS<SUB>2</SUB> thin films on p-Si substrates to form p-n heterojunctions and then transferring Au nanomeshes prepared in a novel surface treatment as transparent top electrodes onto MoS<SUB>2</SUB>. The circular n-MoS<SUB>2</SUB>/p-Si heterojunction solar cell exhibited a power conversion efficiency of 5.96% at a diameter of 0.3 in. and proved to be easily scalable to 1-in. diameter with 5.18% efficiency. To the best of our knowledge, the solar cells of this study are the most efficient and the largest in all types of solar cells based on TMDC reported so far. Finally, based on finite difference time-domain simulation, we proposed a strategy for implementing n-MoS<SUB>2</SUB>/p-Si heterojunction solar cell with efficiency higher than 15% by introducing optimal doping control of n-MoS<SUB>2</SUB> and efficient anti-reflection layers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The large scale, uniform (4-in.) MoS<SUB>2</SUB> thin films are synthesized. </LI> <LI> High transparent, low sheet resistances electrodes are fabricated in a novel way. </LI> <LI> The efficient MoS<SUB>2</SUB> based solar cells are developed by all transfer process including top electrodes. </LI> <LI> The highest, largest MoS<SUB>2</SUB> p-Si/ heterojunction solar cells are demonstrated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P> <B>The highest performance (5.96%), largest area (1 in.) n-MoS2/p-Si solar cells with transparent electrodes fabricated by a novel way.</B> The transparent electrodes lowers the series resistance of the fabricated solar cells, facilitating the collection of photo-generated carriers from the junction. In our knowledge, we have achieved the highest photovoltaic performance at largest active area by using transparent nanomesh electrode among TMDC based solar cells.</P> <P>[DISPLAY OMISSION]</P>