Photovoltaic materials group

Some 60 dyes have been selected as possible photovoltaic materials their electrochemical redox potentials, surface adsorption, spectroscopic properties, fluorescence yields, and acid-base properties have been measured. The aim of this work is to produce a low-cost panel for harvesting solar energy as electrical power. The physical principles of fluorescent solar collectors have been discussed by Raue and Harnisch and several classes of dyes examined. Coumarin dyes are suitable convertors, particularly if the amino-group is fixed by ring closure to the aromatic system. 

In 1995, Heeger and eo vorkers introduced the bulk-heterojunction (BHJ) structure by simply blending polymer and fullerene as active materials, whieh is considered the best PSC device architecture. The extensive studies of donor polymer photovoltaic materials have been well discussed and reviewed.Although thousands of donor polymers with different backbones and side groups have been developed, synthesized and applied in PSCs, donor polymers ean be roughly classified into two types according to their struetures, namely the elassical and novel donor polymers. 

Attaching perylene moieties as side groups allows achievement of high concentration without affecting the electronic structure of the polymer backbone. Putting 16% perylene moieties as side chains predictably results in more efficient energy transfer, observed with polymer 360, both in solution and solid state (emission band at 599 nm). Although no PLED device with 360 has been reported, this material showed excellent performance in solar cells (external photovoltaic QE = 7%, in blend with PPV) [434]. 

The choice of the R group leads to materials exhibiting properties which can find applications in diverse fields long alkyl chains help solubilization in organic solvents, whereas triethylene glycols have been used as spacers to attach water-solubilizing moieties, or even electron-donor systems such as ferrocene, which may find applications in photovoltaics, or as bio- and electrochemical sensors [33]. 

In spite of this extreme experimental simplicity, nnderstanding the mechanisms involved in the deposition and the ability to widen the range of deposits obtained—both in composition and the control of numerous other properties—is usually not so simple. Also in spite of its simplicity, it has not been exploited as a techniqne as mnch as might be expected. However, CD has experienced somewhat of a renaissance recently, due largely to its overwhelmingly snccessfnl nse in depositing bnffer layers of CdS (and similar materials) in thin-film photovoltaic cells. The deposition of the CdS, as with many other semiconductors that have been deposited by CD, is often recipe oriented there seem to be almost as many different recipes as there are groups. 

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