An excitonic solar cell (XSC) is characterized by the formation of an exciton that is produced when a photon from light is adsorbed by the light harvesting molecule. An exciton is a tightly bound electron-hole pair which must be split for charge generation. The exciton dissociation takes place at the interface between the constituent semiconductors. Nanostructuration of interfaces is a crucial approach toward highly efficient devices.
There are (among several) three general types of XSCs: Organic (OSC), Hybrid (HSC) and Dye Sensitized Solar Cells (DSC). Other types are the quantum dot- sensitized Solar Cells (QDSC), the Extremely Thin Absorber solar cell (ETA) or the solid-state version of the DSC, the solid-state Dye sensitized solar cell (ss-DSC).
XSCs can be calssified by the type of material used (organic semiconductors, inorganic semiconductors, etc) or by the type of n-p junction (bi-layer, electrochemical junction, bulk heterojunction, etc).
Organic : C60 derivatives (PCBM), Polymers (P3HT), Small Molecules, etc.
Inorganic : TiO2, ZnO, CdSe, Nb2O5, InS3, Sb2S3, NiO, WO3, MoO3, etc.
Electron transport Materials (ETM): PCBM, TiO2, CdS, CdSe, etc
Hole Transport Materials (HTM): P3HT, PEDOT, Spiro- OMeTAD, NiO, V2O5, etc
Light Harvesting Material (LHM): Dyes, QD, Polymers like P3HT can also harvest light