Solid‐state dye‐sensitized and bulk heterojunction solar cells using TiO₂ and ZnO nanostructures: recent progress and new concepts at the borderline

Abstract

In the field of photovoltaic energy conversion, hybrid inorganic/organic devices represent promising alternatives to standard photovoltaic systems in terms of exploiting the specific features of both organic semiconductors and inorganic nanomaterials. Two main categories of hybrid solar cells coexist today, both of which make much use of metal oxide nanostructures based on titanium dioxide (TiO 2 ) and zinc oxide (ZnO) as electron transporters. These metal oxides are cheap to synthesise, are non-toxic, are biocompatible and have suitable charge transport properties, all these features being necessary to demonstrate highly efficient solar cells at low cost. Historically, the first hybrid approach developed was the dye-sensitized solar cell (DSSC) concept based on a nanostructured porous metal oxide electrode sensitized by a molecular dye. In particular, solid-state hybrid DSSCs, which reduce the complexity of cell assembly, demonstrate very promising performance today. The second hybrid approach exploits the bulk heterojunction (BHJ) concept, where conjugated polymer/metal oxide interfaces are used to generate photocurrent. In this context, we review the recent progress and new concepts in the field of hybrid solid-state DSSC and BHJ solar cells based on TiO 2 and ZnO nanostructures, incorporating dyes and conjugated polymers. We point out the specificities in common hybrid device structures and give an overview on new concepts, which couple and exploit the main advantages of both DSSC and BHJ approaches. In particular, we show that there is a trend of convergence between both DSSC and BHJ approaches into mixed concepts at the borderline which may allow in the near future the development of hybrid devices for competitive photovoltaic energy conversion.

In situ syntheses of semiconducting nanoparticles in conjugated polymer matrices and their application in photovoltaics.

“…The infiltration method for the preparation of organic/ inorganic hybrid layers is well-known for metal oxide/polymer composites [24,55], but recently also a related method for the preparation of metal sulfide nanostructures (e.g. nanosheet arrays, nanoflakes) of In 2 S 3 [125], Ag 2 S [126], and Bi 2 S 3 [127] was used.…”

Design and tailoring of patterned ZnO nanostructures for energy conversion applications

“…Photovoltaic (PV) technology is able to convert sun's energy to electricity through solar cells [101]. The device performance is closely related to the generation and separation of photogenerated charges [102][103][104][105]. To improve the performance of PV solar cells, it is important to fabricate photoanodes with high lightharvesting ability, direct electron transport channel, and efficient carrier collection [106][107][108].…”

Surface modification of dye-sensitized solid-state solar cells by plasma jet

“…DSSCs have the disadvantage of leaks and deterioration of electrolytic solution. The dye-sensitized solid-state solar cells (DSSSCs) could have the potential to be alternatives to the existent DSSCs [6][7][8]. DSSSCs use CuI as solid electrolyte, which does not leak from the cell and does not deteriorate.…”