P3HT-Based Solar Cells: Structural Properties and Photovoltaic Performance

Abstract

Each year we are bombarded with B.Sc. and Ph.D. applications from 8 students that want to improve the world. They have learned that their future depends 9 on changing the type of fuel we use and that solar energy is our future. The hope and 10 energy of these young people will transform future energy technologies, but it will 11 not happen quickly. Organic photovoltaic devices are easy to draw AU1, but the mate-12 rials, processing steps, and ways of measuring the properties of the materials are 13 very complicated. It is not trivial to make a systematic measurement that will 14 change the way other research groups think or practice. In approaching this chapter, 15 we thought about what a new researcher would need to know about organic 16 photovoltaic devices and materials in order to have a good start in the subject. [1][2][3][4]. Similar 43 to the gold rush in the 1800s and the oil boom in the 1900s, intellectual property on 44 new technologies is now the boom industry for innovative people to become rich 45 and influential fast. In the twenty-first century, scientists and engineers are the 46 pioneers and our ideas are the prize. One of the most alluring energy technologies of 47 the past decade has been organic photovoltaics (OPV). This technology is alluring 48 because it could potentially reduce the cost of producing photovoltaic 49 (PV) modules and thereby make solar energy cost-competitive with fossil fuels. 50 As can be seen in Fig. 1, the allure of OPV brought thousands of scientists and 51 engineers into this new field, generating an exponential increase in scientific 52 knowledge (as measured by the number of scientific AU4 articles) in this area. The 53 sharp focus on OPV technology has led to an explosion of interest in enabling 54 technologies such as polymer synthesis, polymer physics, microstructural measure-55 ment techniques, multiscale modeling, photophysics, organic electronics, organic-56 inorganic hybrid materials, etc. All of this intense focus into one research area has 57 also created intense competition between research groups. With so many new 58 scientific articles published yearly, it is impossible to read them all, and repeat or 59 redundant articles have become unfortunately and unavoidably common. Even 60 review articles and books about OPV have proliferated, making production of an 61 original perspective difficult and a complete literature review impractical. We 62 apologize in advance if any important work is not cited here. 63Under this backdrop, we have decided to produce an article that is designed to be 64 helpful to students and postdocs who are entering this field. Rather than focusing on 65 the efficiency of devices or the morphology of materials (subjects that are covered 66 very well elsewhere), we instead focus some attention on how to approach OPV 67 research from a more practical (laboratory-based) perspective. Section 1 introduces A.J. Moulé et al. 68OPV devices, modules, and scale-up. Section 2 discusses fabrication of poly-3- Device Characterist...

Nanoscale Morphology of Doctor Bladed versus Spin‐Coated Organic Photovoltaic Films

“…65,66 Annealing increases the volume fraction of donorrich phase, the connectivity is also increased substantially. 67 Here it is also clear that spin-cast samples have higher donor phase connectivity both before and after annealing, which should indicate better transport of holes to the anode compared to blade cast samples. This result shows that significant research is needed to optimize the blade coating conditions, in particular substrate temperature and solvent to affect drying rate, which in turn can be used to optimize the formation of donor phases.…”

Ionic liquid decoration for the hole transport improvement of PEDOT

“…Based on the non-adiabatic Marcus charge transfer theory, [50][51][52] the hole mobility (m) can be obtained (the calculation details can be seen in the ESI †). Commonly, the order of magnitude of m located in 10 À2 cm 2 V À1 s À1 is moderate among the abundant hole transport materials (o10 À3 cm 2 V À1 s À1 for pristine spiro-linked organic small molecules utilized in the perovskite solar cell, 53 10 À7 cm 2 V À1 s À1 for P3HT typically in organic solar cells, 54 and a record high value of 92.64 cm 2 V À1 s À1 for single crystal PCDTPT nanowires 55 ). Hence, modulating the mobility to 410 0 cm 2 V À1 s À1 for polymeric PEDOT is desirable.…”

Structure–Property Relationship, Glass Transition, and Crystallization Behaviors of Conjugated Polymers

“…Changing solvents, film formation techniques, and annealing processes are the main methods for controlling the structure of films [106]. Annealing processes have been widely applied to pure P3HT films, as well as films containing fullerene blends and their impact on solar cells, at 150 • C isothermal no more than 30 min [107].…”