Ni 도핑된 CoS2와 NiCo2S4를 활용한 차세대 태양전지의 특성연구

김철우 부산대학교 대학원 2018 국내박사

CoS2와 NiS를 기반으로 하는 재료를 염료감응형태양전지(DSSC)와 양자점태양전지 (QDSSC)에 적용할 때 간편하고 저비용으로 효율적인 화학적 배합 방법을 발견했습니다. 이러한 공정은 저온에서의 공정이 가능하고 전기촉매적 특성이 우수하여 기존의 Pt 기반 전지를 대체할 수 있어 경제적이며 환경 친화적입니다. Ni를 도핑시킨 CoS2입자들을 CBD 방식으로 합성하여 FTO에 증착시키는 방식으로 DSSC를 제작하고, NiCo2S4의 고 유한 나노구조를 이용해 FTO에 고품질 박막을 생성하여 QDSSC를 구성했습니다. 제작 된 태양전지들은 태양광 조명 아래 (100mW cm-2, AM 1.5)에서 각각 5.50%, 3.53%의 광전지 변환 효율을 보이고 이는 기존의 Pt 기반 태양전지보다 개선된 수치입니다. 이번 연구에서 제시되는 태양전지 제작 방법은 간단하고 경제적이며 확장성이 뛰어나 많은 분 야에 적용할 수 있는 새로운 방법입니다. We found the chemical formulation method for applying CoS2 and NiS-based materials to dye-sensitized solar cells(DSSC) andquantum dot solar ceslls (QDSSC) in low cost, effective and simple. These processes can be processed at low temperatures and have excellent electrocatalytic properties, making theme conomical and eco-friendly because they can replace existing Pt-based cells. Ni-doped CoS2 particles were synthesized by CBD method and deposited on FTO. DSSC was fabricated by this way and QDSSC was constructed by using NiCoS4 unique nanostructure to produce high quality thin film on FTO. Obtained solar cells have photovoltaic conversion efficiency of 5.50%, 3.53% undere the sunlight illumination (100mWcm-2,AM1.5G) respectively, which is an improvement over the conventional Pt-based solar cell. The solar cell manufacturing method presented in this study, which is simple, economical and highly scalable and one of new method applicable to many fields.

Thiophene과 Triphenylamino quinoline 구조를 가지는 염료감응 태양전지 유기물질합성

조정임 경성대학교 대학원 2011 국내석사

New organic dyes that contain diarylamino substituted quinoline and thiophene moiety have been synthesized. As a key intermediate in the of organic dyes for solar cell applications, we have designed the diarylamino bensophenone containing the diphenylamino moieties. Aldehyde-functionalized thiophene was introduced via Suzuki coupling reaction between bromide (4-(6-bromo-4-phenylquinolin-2-yl)-N,N-diphenylbenzenamine)and bromo(5-formylthiophen-2-ylboronic acid). Vinylene linkgaes having CN and COOH functional group were also achieved by using a Knoevenagel reaction. The chemical structures of synthesized organic dyes were characterized using 1H, 13C-NMR and FT-IR spectrometer. In addition, the optical properties of novel organic dyes were investigated by UV-visible absorption and photoluminescence measurement as solution and thin-film state. Detailed synthetic schemes and characterizations of new donor-acceptor combined organic dyes will be presented.

천연염료인 락-색소를 사용한 염료감응형 태양전지의 특성에 관한 연구

전남진 전남대학교 대학원 2015 국내석사

본 연구에서는 천연염료 중 하나인 락-색소를 이용하여 염료감응형 태양전지의 특성에 관한 연구를 하였다. TiO2 광전극에서 N719와 락색소의 흡착은 Langmuir 흡착등온식으로 잘 설명할 수 있었으며 온도가 증가할 때 흡착량 또한 증가하였다. 열역학 정보로부터 TiO2에서 염료의 흡착은 자발적인 흡열반응임을 알 수 있었다. 회분식 실험을 통해 TiO2에서 N719와 락-색소는 Pseudo-second-order식으로 반응속도를 잘 표현할 수 있었다. 염료감응형 태양전지의 단위셀 I-V 효율은 온도별로 N719의 경우 5.01%, 5.04%, 5.08%로 측정됐고, 락-색소의 경우 증류수를 용매로 하였을 때 0.11%, 0.11%, 0.12%, 에탄올을 용매로 하였을 때 0.13%, 0.14%, 0.16%로 나타났다.

염료감응형 태양전지의 광전극 표면처리에 따른 광전효율 특성

강천수 경북대학교 대학원 2015 국내박사

Dye-sensitized solar cells(DSSCs) have attracted much attention and DSSCs are the subject of many research studies as a third-generation solar cell, because of their high efficiency and low cost of production. The DSSCs have a number of attractive features that it is easy to manufacture by using conventional printing techniques and it is semi-flexible, and semi-transparent which offers a variety of uses not applicable to glass-based systems, and most of the materials are used low cost. In this study, effects of surface modifiers on the performance of solar cells were systematically investigated to improve power conversion efficiency of DSSCs. First, we investigated effects of valeric acid(VA) as a co-adsorbate on the photovoltaic performance of DSSCs. When the introduction of VA onto TiO2 surface was performed after dye adsorption, the DSSCs with VA showed an increase in short-circuit current(Jsc), open-circuit voltage(Voc) and fill factor (FF), resulting in a power conversion efficiency of 7.27 %, compared to that 6.20 % of reference device. It was confirmed that the improvements in both Jsc and Voc were attributed to the prolonged lifetime of electrons injected from dyes to conduction band of TiO2. This increased electron lifetime was probably due to a formation of the insulating layer by VA, which plays a role of energy barrier on free TiO2 surface. Second, we investigated effects of lithium nitrate(LiNO3) as a co-adsorbate on the photovoltaic performance of DSSCs. Voc of DSSCs with a LiNO3 modified TiO2 layer was averagely improved by over 24 % compared to that of a reference device. It was revealed that the modification induced the formation of the surface dipole on the TiO2 electrode, leading to the conduction band edges shift of TiO2 to the negative direction, and thus a larger Voc. We found that DSSCs with the surface modified photoelectrodes, which were treated with VA or LiNO3, showed an improved conversion efficiency, compared to that of conventional device without surface modification.

염료감응형 태양전지용 카본나노튜브 및 백금 상대전극의 특성 비교 연구

구보근 세종대학교 대학원 2008 국내석사

Enhanced performance and stability of dye-sensitized solar cell by using polymeric solid-state and quasi-solid-state electrolyte

장유정 영남대학교 대학원 2020 국내석사

The long-term stability of liquid-state dye-sensitized solar cells (liquid-DSSCs) is a primary problem for the upscaling and commercialization of this technology. The solid-state dye-sensitized solar cell (ss-DSSC) has been instigated to overcome the liquid-DSSC’s inherent production and instability issues and advancement has been made to achieve low-cost high-power conversion efficiency. The photovoltaic performance of ruthenium-based complex Z907 dye was studied in ss-DSSCs using a solid-state polymerized conductive polymer as hole-transporting material (HTM). Weinvestigatedthelong-termstabilityofbothliquidandsolid-stateDSSCsandthefindingsrevealed an improved photovoltaic performance and long-term stability of ss-DSSC. This mainly depends on the transport phenomena of the HTM throughout the interface. The present results show a pavement for manufacturing highly stable and inexpensive ss-DSSC and the practical use is promising.

TCO-less 구조 염료 태양전지의 제작과 광전변환 특성

허종현 경성대학교 대학원 2010 국내석사

Dye-sensitized solar cells (DSCs) are composed of a porous photo-electrode material such as TiO2 layer stained with dye molecules and electrolytes consist of I-/I3- redox system. Transparent conductive oxide (TCO) layer is an important part in the construction of DSCs because of its low sheet resistance, sufficient light transparent ability and high photoelectrical response as a porous photo-electrode material of DSCs. In order to fabricate TCO-less DSCs), Ti films (~580 nm thickness) have been deposited by rf magnetron sputtering method. The TCO-less DSCs sample is composed of a glass substrate/dye-sensitized TiO₂ nanoparticle/Ti layer/electrolyte/Pt coated counter electrode. The Ti layer with high conductivity can collect electrons from the TiO₂ layer and allows the ionic diffusion of I-/I3- through the hole. The vacuum annealing treatment is important with respect to the interfacial necking between the metal Ti and porous TiO₂ layer. The efficiency of prepared TCO-less DSCs sample is about 4.8% (ff: 0.53, Voc: 0.73V, Jsc: 12.4 mA/㎠).

전기화학적 증착법에 의해 합성된 ZnO 나노로드의 성장거동과 TiO2로 표면 처리된 ZnO 나노로드의 광전기화학적 특성에 관한 연구

김진화 경상대학교 대학원 2011 국내석사

Dye-sensitized solar cell (DSSC) is currently the most efficient and stable photocell and is one of the promising alternatives for silicon solar cell, as it possesses advantages such as low cost, simple process, and large-scale production. Nowadays, considerable efforts of DSSC have been invested in morphology control of photoanode film and synthesis of stable optical sensitizers. Besides, due to the encapsulation problem posed by the use of the liquid electrolyte in conventional liquid electrolyte based DSSC, solvent leakage and evaporation are two main challenges; therefore, much work is being done to make a solid-state DSSC. Moreover, the use of quasi-solid-state electrolytes in the DSSC is expected to offer stable performance for the device. DSSC with TiO2 nanoparticle photoanode films have been demonstrated with a power convention efficiency of 11% in which a thick layer of nanoporous film provides a large surface area of anchoring the light harvesting dye molecules. However, slow electron percolation through the interconnected nanoparticles and the charge recombination between injected electrons and electron acceptors in the electrolyte hinder the DSSC performance. A desirable morphology of the film should have the channels parallel to each other and vertically with respect to the substrate such as nanorods arrays. Superior photo-to-electric performance of such oriented film is promising. Then a version of nanorods/nanowires dye-sensitized cells was introduced and got good score. Moreover, in order to anchor more dye and improve charge transfer, an electrode comprised of an oriented architecture with high surface area, such as a highly ordered nanotubes arrays aligned perpendicularly to the surface, was proposed to increase cell efficiency of energy conversion. ZnO is an attractive material for nanoscale optoelectronic devices, because it is a wide band gap semiconductor with good carrier mobility and can be doped both n-type and p-type. Electron mobility is much higher in ZnO than in TiO2, while the conduction band edge of both materials is located at approximately the same level. One would therefore expect nanostructured ZnO to be a good candidate as electron acceptor and transport material in dye-sensitized solar cells. A large range of fabrication procedures is available for ZnO nanostructures, such as sol-gel processes, chemical bath deposition, electrodeposition and vapor-phase processes. Different morphologies such as spherical particles, rods, wires and hollow tubes can be prepared with relative ease. ZnO shows more flexibility in synthesis and morphologies than TiO2. ZnO as the electrode of dye-sensitized solar cell showed very low efficiency. Keis et al. results give evidence for dye agglomeration in the ZnO nanostructured electrodes. The agglomeration is due to the dissolution of Zn+ ions from ZnO in which protons from the carboxylic groups of the dye are active. The dissolution of the Zn2+/dye complexes that agglomerate in the pores of the ZnO matrix. The precipitation of Zn-dye complex aggregates cause interference to the electron exchange between electrolyte and dye which prevent high electron injection efficiency. In this work, the growths of well aligned ZnO nanorods with high surface area were synthesized by aqueous solution using an electrochemical deposition process. And the aligned TiO2/ZnO nanorods arrays were fabricated by surface treatment method assisted by ZnO nanorods templates. Furthermore, as an application of the ZnO and TiO2/ZnO nanorods, dye-sensitized solar cells based on them (nanorods DSSCs) were successfully fabricated and the cell performances were characterized.

n- 및 p-type 염료감응태양전지의 광감응 염료구조 최적화

최석균 영남대학교 대학원 2014 국내석사

1991년 스위스의 M. Grätzel교수가 발표한 염료감응 태양전지는 차세대 태양전지로 기존의 실리콘 태양전지를 대체할 수 있는 새로운 형태의 에너지원으로서 상당한 관심을 끌고 있다. 본 연구에서는 차세대 염료감응 태양전지에 들어가는 여러 가지 소재 분야 중에서 빛을 흡수하여 전자가 생성되는 가장 핵심적인 소재인 유기염료합성 연구를 진행하였다. 본 연구는 전자밀도가 풍부해 electron doner로써 널리 사용하고 있는 Tripenylamine을 이용한 electron brige, electron acctepter를 적절히 배치 함으로서 효율을 극대화 하는 실험을 진행하였고, 그 외에 염료감응형 태양전지에 사용되는 전해질 부분에서 Iodine을 이용한 액체전해질과, polymer를 이용한 준 고체 전해질을 이용하여 특성평가를 진행 하였다. 그 외에 높은 구동 전압을 위해 구조적인 hybrid형 p-,n- 염료감응태양전지를 제작하기 위해 p-형 염료감응형 태양전지가 필요로 하다. 그래서 p-형 반도체인 NiO를 이용하여 전극을 형성하였고 구조에 적절한 염료를 합성하는 연구를 진행하였다. 그 결과 n-형 염료감응태양전지 에서는 Triphenylamine을 이용하고, 액체 및 준 고체 전해질을 적용한 연구에서는 안정성과 효율을 확보하는 연구를 진행 할 수 있게 되었고,p-형 염료감응태양전지는 높은 구동전압을 형성 할 수 있는 전극과 염료를 확보 할 수 있는 연구를 진행하였다.

강유전체 물질인 Fe-BLT를 TiO2 광전극에 응용한 염료감응형 태양전지 제작 및 특성 : Dye-sensitized solar cell fabrication using ferroelectric materials of Fe-BLT applied TiO2 photoelectrode

송명근 가천대학교 일반대학원 2016 국내석사

본 논문에서는 복합산화물중 비스무스 티타나이트(Bismuth titanate)를 기반으로 한 파우더의 입자 크기를 조절하여 Fe-BLT(Bi3.25La0.75)(FeTi2)O12 의 밴드갭(Bandgap)을 제어 하고 이를 염료감응형 태양전지에 응용하였다. 기존의 밴드갭을 제어하는 기술은 4주기 원소(Ti, V, Cr, Mn, Co, Ni Al)등을 도핑(Doping) 하여 치환하는 방법 또는 추가적인 열처리를 통해 구조 내부에 산소 공석(Oxygen Vacancies)를 생성시켜 결함(Defect)을 발생시켜 이를 통해 밴드갭을 제어하는 방법 등이 있었다. 하지만 치환을 통한 밴드갭 제어는 밴드갭을 크게 제어할 수는 없었고 산소 공석을 생성시키는 방법은 적절한 열처리 조건을 찾는데 큰 어려움이 있었다. 고 에너지 볼밀(high-energy ball milling) 과정을 통해 입자의 크기를 나노 크기로 줄임으로써 입자 표면에 자연적으로 산소 공석을 발생시켜 밴드갭을 제어하여2.08eV에서 1.77eV까지 밴드갭을 감소시켰다. 밴드갭이 제어된 Fe-BLT파우더를 염료감응형 태양전지에 응용하기 위해 TiO2 광전극 제조시 비율별로 Fe-BLT 파우더를 넣었다. 하지만 TiO2 와 비스무스 티탄산 계열 물질인 Fe-BLT가 섞인 광전극을 염료에 24시간 넣어다 뺀 뒤, 과량으로 흡착된 염료를 세척하는 과정에서 FTO 기판과 광전극이 분리되는 현상이 발생하였다. 이를 방지하기 위하여 자외선(UV-O3)를 이용하여 비스무스 티탄산 계열 물질의 습윤성을 제어하였다. 그 결과 FTO 기판과 광전극이 분리되는 현상을 방지할 수 있었다. 마지막으로 Fe-BLT가 들어간 염료감응형 태양전지의 효율을 증가시키기 위하여 강유전물질의 분극현상을 이용하였다. 셀 제작 시 전해질 주입 과정 전에 셀 양단에 20MV/m 의 직류 전압을 인가해 주었다. 전압을 인가하게 되면 강유전물질은 한 방향으로 정렬하게 된다. 강유전물질이 한 방향으로 정렬된 태양전지와 그렇지 않은 태양전지의 효율을 비교해 본 결과 약 77%의 효율 상승이 있었다. 이러한 방법은 강유전물질을 이용한 다른 태양전지에도 응용될 수 있음을 보고한다. The Dye-sensitized solar cell(DSSC) is variety of studies have been conducted due to excellent in a cost-competitive and excellent reliability than the conventional silicon solar cell. DSSCs have been broadly researched over the last 25 years as cheaper alternatives to silicon solar cells. However, much of the effort aimed at achieving high conversion efficiencies. Recently, lanthanum-modified bismuth titanate has been suggested to have potential applications in nano-electronics and nano-optoelectronics. But, these materials have a wide band gap than other materials for photoelectric applications. Further reducing optical band gap of BLT, we used chemical doping and oxygen doping. Doped with iron in BLT for chemical doping and reducing particle size for oxygen doping. In this report, we work the photovoltaic characteristics of DSSCs fabricated by mixing TiO2 with Fe-BLT. These nanosized Fe-BLT powders were prepared by a high-energy ball milling process. The TiO2 nanoparticles and nanosized Fe-BLT powders were mixed various ratios. Furthermore, 20MV/m DC bias was applied to the DSSC cell. With the optimal concentration of nanosized Fe-BLT doping in the electrode, the cells light-to-electricity conversion efficiency could be improved 64% compared to that without applying DC bias.