Acetylene-substituted PPV derivatives can be synthesized via the Wittig – Horner Reaction (Figure 15). The coplanar and rigid nature of the acetylene moiety in the polymer chain may have the potential to obtain a higher degree of packing and thus improve the photovoltaic performance of such devices. Having coplanar electron-rich anthracene units and triple bond […]

Cyano-substituted poly(p-phenylene-vinylene)s (CN-PPV) with electron deficient cyano groups on the vinyl units are synthesized by Knoevenagel polycondensation polymerization of terephthaldehyde and 1,4-bis(cyanomethyl)benzene in the presence of the base f-BuOK (Figure 12). Hence, the LUMO and HOMO levels of PPV derivatives can also be tuned by incorporating electronic substituent into the vinylene bridges (Cheng et al., […]

1.2 Poly(p-phenylene-vinylene) and its derivatives Poly(p-phenylene-vinylene)s (PPVs) and its derivatives are one of the most promising classes of conjugated polymers for organic solar cells due to their ease of processability as well as tunability of their optical and electronic properties through chemical modifications. Since the first report of electroluminescence from PPV, a great research attention […]

Conjugated polymer thin films sandwiched between two metal electrode are usually described using a metal-insulator-metal (MIM) picture (Parker, 1994). The different operating regimes the MIM device due to externally applied voltages is shown in Figure 3. As illustrated in Figure 3(a), the vacuum levels (Evac) of the stacked materials shall align themselves (Shottky-Mott model). Figure […]

The sequential process involved in the light into electricity conversion can be summarized by the following steps: First, incident light is absorbed within the photoactive layer leading to the created of a bound electron-hole pairs (singlet excitons); the created excitons start to diffuse within the donor phase leading to charge separation; the separated charge carriers […]

1.1 A brief history The first organic solar cells consisted of a single layer of photoactive material sandwiched between two electrodes of different work functions (Chamberlain, 1983; Wohrle & Meissner, 1991). However, due to the high binding energy of the primary photoexcitations, the separation of the photogenerated charge carriers was so inefficient that far below […]

Cigdem Yumusak12 and Daniel A. M. Egbe2 1Department of Physics, Faculty of Arts and Sciences, Yildiz Technical University, Davutpasa Campus, Esenler, Istanbul, 2Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University of Linz, Linz, 1Turkey 2Austria 1. Introduction Since the discovery of electrical conductivity in chemically doped polyacetylene (Shirakawa et al., 1977; […]

Although conventional SCs based on inorganic materials specially Si exhibit high efficiency, very expensive materials and energy intensive processing techniques are required. In comparison with the conventional scheme, the hybrid Si-based SC system has advantages such as; (1) Higher charging current and longer timescale, which make the hybrid system have improved performances and be able […]