계면 공정을 통한 고성능의 카본 전극 기반 페로브스카이트 태양전지 제조

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 화학생물공학부(에너지환경 화학융합기술전공), 2020. 8. 장정식.Perovskite solar cells (PSCs) based on organic-inorganic halide perovskite (ABX3 structure) have rapidly developed as one of the most potent next-generation photovoltaic devices based on their extraordinary optical and physical properties. The photovoltaic performance of PSC, which has been swiftly improving to date, is comparable to commercial-silicon solar cells. In recent years, research trends are turning into real problems related to the actual use of PSCs in daily life, such as large-scale modularization, long-term stability, and toxicity testing for commercialization of PSCs. In particular, in terms of stability, decomposition of the perovskite by external stress factors (e.g. moisture, air, heat and etc.) and deterioration at the interface between a metal electrode and charge transport layer are important issues to be solved. Besides, it is necessary to ameliorate process efficiency due to the introduction of expensive metal electrodes and charge transport layers through a complicated process. One of the best alternatives to solving these problems is the manufacture of PSCs using a carbon electrode, which is an inexpensive and stable material and doesnt require the hole conductor. Carbon electrode-based perovskite solar cells (C-PSCs) not only have high stability against moisture and thermal stress but also can be manufactured by introducing electrodes through various methods (e.g. screen printing, doctor blading, spraying, roll to roll, etc.), making PSCs suitable for mass production and enlargement. However, despite process efficiency and device stability, C-PSCs are less efficient than conventional metal electrode-based PSCs because of poor physical and chemical contact between the carbon electrode and the perovskite light-absorbing layer. Therefore, for practical use of C-PSCs, it is necessary to fabricate a high performance and highly stable C-PSC by the improvement of interfacial contact. This dissertation describes the effective strategies to improve interfacial contact between the carbon electrode and perovskite in fabricating the C-PSCs through interface engineering based on various processes and materials. Specifically, the introduction of organic and inorganic materials through a solution process to induce the growth of the interfacial layer or adjusting the interfacial energy level of carbon electrode through a plasma process. Firstly, a two-dimensional perovskite (2D PSK) interfacial layer was introduced on a fabricated C-PSC using a bulky organic ligand (phenylethyl ammonium iodide, PEAI) solution. Introduced 2D PSK interfacial layer improved hole extraction ability, and inhibited interfacial charge recombination due to the aligned energy level. These results induced the performance of C-PSC. Also, it was confirmed that the stability of the device was further improved because the 2D PSK has high moisture and thermal stability. Secondly, a colloidal lead iodide (PbI2) capped with organic acids, that can be dispersed in a non-polar solvent was additionally introduced at the interface of the carbon/perovskite for the enhanced the interfacial contact. The prepared colloidal PbI2 was introduced at the interface without damaging the fabricated C-PSCs, and secondary growth of methylammonium lead iodide (MAPbI3) interfacial layer was induced by additional MAI (methylammonium iodide) treatment on the colloidal PbI2-treated C-PSC. Secondary growth of the MAPbI3 interfacial layer significantly improved device performance by maximizing the interfacial contact between the carbon electrode and perovskite layer compared to previous studies that induced performance enhancement by the additional introduction of organic ligands. Moreover, the device stability was improved due to the hydrophobic organic acid present during the formation of the interfacial MAPbI3 layer. Thirdly, the carbon electrode, in which fluorine atoms were introduced in a concentration gradient, was prepared based on the plasma process. As fluorine atoms having strong electron-withdrawing properties, were introduced into the carbon electrode, the work function of the carbon electrode and the HOMO energy level of the perovskite are well aligned with each other, thereby improving hole transporting ability, followed by the enhanced device performance. In addition, hydrophobic fluorine atoms were introduced into the hydrophobic carbon electrode, and C-PSCs having maximum moisture stability was produced by synergy effect. Accordingly, this study provides several strategies to further improve the long-term stability of PSCs, as well as how to improve the performance of C-PSC through various processes and materials-based interface engineering.유기-무기 할라이드 페로브스카이트를 기반으로 한 페로브스카이트 태양전지는 뛰어난 광학적 및 물리적 특성에 기초하여 가장 강력한 차세대 광전지 중 하나로 급속히 발전해왔다. 현재까지 빠르게 개선된 페로브스카이트 태양전지의 광기 전 성능은 상업용 실리콘 태양전지에 필적한다. 최근 연구 추세는 페로브스카이트 태양전지의 상용화를 위한 대규모 모듈화, 장기 안정성 및 독성 테스트와 같이 일상 생활에서 페로브스카이트 태양전지의 실제 사용과 관련된 실제 문제로 바뀌고 있다. 특히 안정성 측면에서 페로브스카이트의 수분, 대기 및 열에 의한 분해의 저하와 금속전극 및 전하이동층과의 계면 열화는 반드시 해결해야할 문제이다. 더 나아가, 고가의 금속전극 및 전하이동층 도입의 공정 효율성이 떨어지는 부분도 개선해야할 사항이다. 이러한 문제를 해결하기 위한 대안 중 하나는 저렴하고, 안정적인 카본 전극을 이용하여 정공 전도체 없이 페로브스카이트 태양전지를 제조하는 것이다. 카본 전극 기반 페로브스카이트 태양전지는 높은 수분 및 열 안정성을 가질 뿐만 아니라 다양한 전극 도입 방법을 통해 제조될 수 있으므로, 대량 생산 및 소자 대형화에 적합하다. 그러나, 이와 같은 공정 효율성 및 장치 안정성에도 불구하고, 카본 전극 기반 페로브스카이트 태양전지는 카본층과 페로브스카이트 광 흡수층 사이의 물리적 / 화학적 접촉이 불량하기하므로 종래의 금속 전극 기반 페로브스카이트 태양전지보다 효율이 떨어진다. 따라서 카본 전극 기반 페로브스카이트 태양전지의 실제적 상용화를 위해서는 계면 접촉성 향상을 통해 고성능, 고안정화된 카본 전극 기반 페로브스카이트를 제조할 수 있어야 한다. 본 논문에서는 다양한 공정 및 물질을 기반으로 한 계면 엔지니어링을 통해 카본 전극 기반 페로브스카이트 태양전지를 제조할 때 탄소 전극과 페로브스카이트의 계면 접촉을 개선하는 효과적인 전략을 제시하였다. 자세하게는, 용액 공정을 통해 유기 및 무기 물질을 도입하여 계면 층의 성장을 유도하거나 플라즈마 공정을 통해 탄소 전극의 계면 에너지 수준을 조정하였다. 첫 번째로, 부피가 큰 유기 리간드 (페닐에틸암모늄요오드) 용액을 이용하여 제조된 페인팅된 카본 전극 기반 페로브스카이트 태양전지 상 처리하여, 2차원 페로브스카이트 계면층을 도입하였다. 도입된 2차원 페로브스카이트 계면층은 정렬된 에너지 레벨 수준을 제공하며, 정공 추출 능력 향상과 계면 전하 재결합을 억제하였다. 이를 통해 카본 전극 기반 페로브스카이트 태양전지 성능을 향상시켰다. 또한, 2차원 페로브스카이트는 수분 및 열 안정성이 높아 소자의 안정성을 더욱 높이는 것을 확인하였다. 두 번째로, 계면 접촉성을 더욱 향상시킨 페로브스카이트 계면층을 형성하기 위해, 무극성 용매에 분산될 수 있는 유기산으로 둘러쌓인 콜로이드 PbI2 를 제조하였다. 제조된 콜로이드 PbI2는 제조된 카본 전극 기반 페로브스카이트 태양전지에 소자 손상 없이 계면에 도입되었으며, 추가적인 메틸암모늄 요오드 처리를 통해 MAPbI3 계면층의 이차성장을 유도하였다. MAPbI3 계면층의 이차성장은 유기 리간드 처리만으로 잔존하는 PbI2와 반응시키는 이전 연구들과 비교하였을 때, 카본 전극과 페로브스카이트 계면 접촉성이 극대화되며 소자 성능이 크게 향상되었다. 또한, 계면층이 형성될 때 존재하는 소수성 유기산들에 의해 소자 안정성 향상에 기인하였다. 셋째로, 플라즈마 공정을 기반으로 불소가 농도 구배로 도입된 카본 전극을 제조하였다. 전자 끌개 특성이 큰 불소가 카본 전극에 도입되며 전극의 일 함수와 페로브스카이트의 호모 레벨의 에너지 레벨 수준 정렬에 따라 정공 수송 능력 향상되며 소자의 성능을 향상을 유도하였다. 더 나아가 소수성 불소 원자가 소수성 카본 전극에 도입되며 시너지 효과로 수분 안정성이 극대화된 카본 전극 기반 페로브스카이트 태양전지를 제조할 수 있었다. 따라서 본 논문은 다양한 공정/물질을 바탕으로 한 계면 엔지니어링을 통해 카본 전극 기반 페로브스카이트 태양전지의 성능 향상 방법을 제시할 뿐만 아니라 소자의 장기 안정성까지 더욱 향상시킬 수 있는 전략을 제시한다.1. Introduction 1 1.1. Background 1 1.1.1. Organic-inorganic halid perovskite solar cells (PSCs) 1 1.1.2. Device architecture and fabrication of PSCs 8 1.1.3. Carbon electrode-based PSCs (C-PSCs) 13 1.1.4. Interface engineering of PSCs 19 1.1.4.1. Interface engineering based on solution process 23 1.1.4.1.1. 2D/3D hybrid PSCs based on bulk organic ligands 29 1.1.4.1.2. Interfacial passivated-PSCs based on excess PbI2 36 1.1.4.2. Interface engineering based on plasma process 44 1.2. Objectives and Outlines 49 1.2.1. Objectives 49 1.2.2. Outlines 50 2. Experimental Details 52 2.1. Interface engineering of C-PSCs based on 2D perovskite interfacial layer 52 2.1.1. Fabrication of C-PSCs with 2D perovskite interfacial layer 52 2.1.2. Characterization of C-PSCs with 2D perovskite interfacial layer 55 2.2. Interface engineering of C-PSCs based on secondary growth of MAPbI3 interfacial layer 57 2.2.1. Preparation of Colloidal PbI2 Solution 57 2.2.2. Fabrication of C-PSCs with secondary growth of MAPbI3 interfacial layer 57 2.2.3. Characterization of C-PSCs with secondary growth of MAPbI3 interfacial layer 59 2.3. Interface engineering of C-PSCs based on energy level adjustment via F-plasma treatment 63 2.3.1. Fabrication of C-PSCs with F-doped carbon 63 2.3.2. Characterization of C-PSCs with F-doped carbon 65 3. Results and Discussion 67 3.1. Interface engineering of C-PSCs based on 2D perovskite interfacial layer 67 3.1.1. Fabrication of interface-engineered C-PSCs with 2D perovskite 67 3.1.2. Photovoltaic performance of interface-engineered C-PSCs with 2D perovskite 79 3.1.3. Interfacial charge carrier dynamics in interface-engineered C-PSCs with 2D perovskite 88 3.1.4. Device stability of interface-engineered C-PSCs with 2D perovskite 97 3.2. Interface engineering of C-PSCs based on secondary growth of MAPbI3 interfacial layer 102 3.2.1. Synthesis of colloidal PbI2 and fabrication of C-PSCs with MAPbI3 interfacial layer 102 3.2.2. Characterization of colloidal PbI2-based MAPbI3 interfacial layer 115 3.2.3. Photovoltaic performance of C-PSCs with MAPbI3 interfacial layer 124 3.2.4. Interfacial charge carrier dynamics in C-PSCs with MAPbI3 interfacial layer 132 3.2.5. Device hysteresis and long-term stability of C-PSCs with MAPbI3 interfacial layer 147 3.3. Interface engineering of C-PSCs based on energy level adjustment via F-plasma treatment 153 3.3.1. Fabrication of F-doped C-PSCs 153 3.3.2. Photovoltaic performance of the F-doped C-PSCs 162 3.3.3. Interfacial charge carrier dynamics in F-doped C-PSCs 170 3.3.4. Ambient and moisture stabilities of F-doped C-PSCs 178 4. Conclusion 184 References 189 국문초록 204Docto

다이할로벤젠으로부터 아세트아미노펜을 합성하는 구리촉매화 공정연구

학위논문 (석사)-- 서울대학교 대학원 : 화학생물공학부, 2013. 2. 김영규.Up to now, various kind of non-opioid analgesic drugs have been developed and their developments have been progressed to the improvement or the complement of weak point of the former analgesics at each time. In these days, one of them, acetaminophen (1) is known for the most widely used analgesics in the world on the account of the many advantages in terms of the medicinal application and few adverse effects in comparison with other analgesics. However, the former synthetic process of acetaminophen (1) have many problems such as, generation of undesired isomer and use of strong, toxic acid and so on. These problems accompany additional purification steps and recycle of waste acids, finally, bring about the additional cost that affect the production cost of acetaminophen (1). In this paper, we are going to discuss our efforts to develop both an efficient and an economic process for acetaminophen (1) using Cu-catalyzed reaction from dihallobenzenes. We could not only improve the drawbacks of the former synthetic process, but also could make the synthetic process more eco-friendly under mild reaction conditions and the synthetic steps shorter without the additional purification.ABSTRACT................................................................ ⅰ LIST OF FIGURES................................................................... ⅲ LIST OF TABLES.................................................... ⅴ LIST OF SCHEMES................................................. ⅷ LIST OF ABBREVIATIONS....................................... ⅸ Introduction…...................................................... 1 1. History of non-opioid analgesic drugs................... 3 1.1. Salicylic acid..................................................... 3 1.2. Antipyrine, Pyradon and dipyrone...................... 5 1.3. Aspirin................................................................ 8 1.4. Paracetamol (Acetaminophen)........................ 10 2. Research plan....................................................... 14 2.1. Former synthetic process............................... 14 2.2. New synthetic process.............................15 Results and discussion.................................................... 19 1. Acetamidation............................................... 20 1.1. Screening of the amount of acetamide................. 20 1.2. Screening of Cu-catalysts............................... 21 1.3. Screening of bases......................................... 23 1.4. Screening of ligands........................................... 25 1.5. Screening of solvents...........................................28 1.6. Screening of reaction times............................... 30 1.7. Screening of temperatures............................. 31 1.8. Pressure, another factor for results.......................... 32 1.9. Application to other substrates............................ 35 2. Hydroxylation.........................................................37 2.1. Screening of Cu-catalysts................................. 37 2.2. Screening of bases............................................. 39 2.3. Screening of ligands......................................... 41 2.4. Screening of solvents......................................... 43 2.5. Screening of reaction times.................................. 45 2.6. Screening of temperatures........................... 46 2.7. Endeavor to decrease the amount of acetanilide.......47 2.8. Application to other substrates........................49 Conclusion........................................................ 51 Experimental details....................................... 53 APPENDICES..................................................... 57 REFERENCES.......................................................... 65 ABSTRACT IN KOREA............................................... 67 ACKNOWLEDGEMENT..................................... 68Maste