Hybrid solar cells with novel hole transporting poly (triphenyldiamine)s

Dye-sensitized hybrid solar cells with a nanoporous TiO2 layer and differen t organic hole conducting polymers based on triphenyldiamines (TPD) have be en investigated. These hole transport materials (HTM) have low glass temper atures (T,). The penetration behaviour of HTM into the nanoporous layer has been determined by scanning electron microscopy (SEM) measurements. The ef fect of the penetration depth and wetting of the dye sensitized TiO2 layer by HTM on the solar cell efficiencies have been tested with I-V-characteris tics and steady-state measurements. To improve the filling of the nanoporou s layer, the polymers were heated above T,. Although a higher penetration c ould be seen, the performance of the cell is decreasing, probably due to de gradation of the dye during thermal treatment.