esrによる高效率有机太阳电池の 高效率有机太阳电池の 高效率有机 ....pdf

ESRにESRによるよる高効率有機太陽電池の高効率有機太陽電池の評価と素子評価と素子特性向上特性向上 ESRESRにによるよる高効率有機太陽電池の高効率有機太陽電池の評価と素子評価と素子特性向上特性向上 筑波大数物、筑波大学学際センター 丸本一弘 数理物質融合科学センター（CiRfSE）第１回ワークショップ、筑波大学、 つくば、2015年3月5日 Outline 1. Electron spin resonance (ESR) New analytical method of organic solar cells 2. ESR study of organic solar cells Direct observation of charge accumulation during device operation 1) P3HT:PC61BM blend films Power conversion efficiency 3.5% 2) PTB7:PC71BM blend films High power conversion efficiency 8.5% Light-induced ESR and performance of devices ⇒analyze the internal states of solar cells Intrinsic deterioration mechanism 3. Summary Why ESR is useful for organic devices? Traditional research methods for organic devices • Electrical measurements (current, voltage,…) • Scanning microscopes (AFM, STM,…), etc. cannot directly observe internal states in organic devices. Understanding of device operation Improvement of device performance Advantages of ESR for organic devices: • In situ direct observation of internal states in organic devices • High sensitive and high precision analysis at molecular level ~1010 spins are enough for ESR measurement • Quantitative measurements of charges with spins in devices First ESR application to organic devices was reported in 2004 J. Phys. Soc. Jpn. 7 (2004) 1673. Principal of ESR and system High sensitive and precision analytical method Evaluation of organic devices at the molecular level Principle of ESR ESR system Electron energy in magnetic field H Microwave Spin Hamiltonian: