ZnO nanorod arrays modified with dye molecules demonstrate specific light-harvesting and charge-collecting properties which are promising for the enhancement of the characteristic performance of hybrid solar cells based on ZnO/poly(3-hexylthiophene). The properties of dyes commonly used for dye-sensitized solar cells were investigated in relation to the performance of polymerÀinorganic hybrid photovoltaic devices. The use of indoline dye D205, which has dipole moments directing away from the ZnO surface, was found to suppress the reverse saturation dark current density and charge recombination and to consequently lead to higher opencircuit voltage and improved power conversion efficiency (PCE) from 0.22% to 0.71%. Derivatized squaraine molecules were synthesized and were found to improve device performance by extending the lightharvesting range to the near-infrared region, leading to increased short-circuit current density and the highest PCE of 1.02%.

The nanorod arrays of ZnO incorporated with lithium atoms show specific crystallinity, photoluminescence and absorption properties, which are promising for the improvement of photovoltaic performance of hybrid solar cells based on ZnO/poly(3-hexylthiophene). Li ions can be incorporated into ZnO crystals during the hydrothermal growth of the nanorods. The presence of Li in ZnO crystal was confirmed through X-ray diffraction analysis and by the photoluminescence spectra obtained. The difference in photovoltaic properties brought about by Li doping were determined from concentrations of the precursor solution. It was determined that appropriate Li doping improves both the short circuit current density (J sc) and open circuit voltage (V oc). The quenching of photoluminescence of Li-doped ZnO nanorods/P3HT films indicates effective charge transfer at the interface due to oxygen-enrichment surface, corresponding to the enhancement of J sc. The improvement of V oc was due to the suppression of 65 (LiNO 3), monoethanolamine (H 2 NCH 2 CH 2 OH), and chlorobenzene (C 6 H 5 Cl) were purchased from Wako Pure Chemical Industries, Japan. Hexamethylenetetramine (C 6 H 12 N 4) and 2-methoxyethanol (C 2 H 8 O 2) were bought from Aldrich.

Incorporation of an effective additive 1,3-diaminoguanidine monohydrochloride in MAPbI3 film can increase the grain size and reduce trap density, consequently increasing the carrier lifetime and reducing charge recombination, leading to an improved efficiency from 19.1% to 20.3% in a p–i–n structured solar cell.

In an organic-based solar cell, the short exciton diffusion length of organic materials requires effective donor-acceptor heterojunction at the nanoscale. In this work, hybrid inorganic/polymer solar cells based on ZnO nanostructures and poly(3-hexylthiophene) (P3HT) are constructed to study the effects of ZnO morphologies and wettability of the surface on the P3HT infiltration ability and charge transport mechanisms. The P3HT infiltrates the ZnO nanorod (NR) more remarkably than ZnO nanoparticle (NP) substrates. Although surface modification with indoline D205 dye molecules improves the wettability (viz. enlarges the contact angle) of NP surface, the P3HT infiltration distance decreases in comparison with the pristine NP case. This leads to relatively low short-circuit current density (Jsc) of the NP devices in comparison with that of the NR devices, even though the surface area of NP layers is larger than that of NR ones. Moreover, surface modification with squaraine dye onto the NR surface shows more significant improvement in Jsc than the NP case. This is due to the well-aligned morphology of the NRs, which facilitates dye modification, P3HT infiltration, and charge transport processes. These indicate that the NRs are more qualified as electron accepting substrates and transport pathway in hybrid solar cells than NPs.