Towards Efficient Hybrid Solar Cells Based on Fully Polymer Infiltrated ZnO Nanorod Arrays

Abstract

A significantly improved efficiency is achieved for solar cells based on hydro­thermally grown ZnO nanorods and P3HT. This efficiency is obtained by fine‐tuning morphological parameters and by adding electron and hole blocking layers. Insight into the mechanisms underlying the improvement lead to recommendations for further future improvements.

ZnO Nanorod Arrays as Electron Injection Layers for Efficient Organic Light Emitting Diodes

“…To aid nucleation and vertical alignment a 130 nm ZnO have reported on having to cast F8BT from 10 mg/ml solutions four times via spin coating in order to create a layer thick enough to fully infiltrate their InGaN/GaN NRA [35] , but few experimental details are given in this respect in other published NR HyLED reports and complete infiltration is often presumed. There are extensive reports within hPV literature, however, that show the need for post-deposition thermal treatment to overcome wetting issues between the polymer and the NRA [20,36,37] .…”

“…Of particular interest for device applications is the growth of ZnO nanorod arrays (NRAs) from low temperature, aqueous deposition techniques [10] which, over the past decade, has seen morphological improvements in alignment and uniformity through the introduction of precursor ZnO seed layers [11] , pH control of the growth environment [12,13] , additive incorporation [14] , as well as manipulation of growth variables including duration and temperature [15][16][17][18] . Efforts to implement nanorod arrays into bulk heterojunction hybrid organic-inorganic photovoltaics (hPV) have led to improved devices attributed to improvements in charge collection [19,20] .…”

Influence of Interface Morphology onto the Photovoltaic Properties of Nanopatterned ZnO/Poly(3-hexylthiophene) Hybrid Solar Cells. An Impedance Spectroscopy Study

“…17,28,41 In this contribution, impedance spectroscopy will be applied to study hybrid solar cells based on ZnO nanorod arrays and P3HT, thereby focusing on interface properties and their relation with device performance upon thermal treatment. Furthermore, charge extraction in a linearly increasing voltage (CELIV) is performed as a complementary technique to obtain additional information about the charge carrier mobility of P3HT as used in devices with and without nanopatterning.…”

“…28 After deposition, the samples were annealed at the melting temperature of P3HT (225°C) in N 2 for different times to enhance infiltration into the nanorods and to enhance the crystallinity of the P3HT. 17 Finally, 80 nm Ag top electrodes were evaporated in vacuum (1 Â 10 À6 mbar). Solar Cell Characterization.…”

“…ZnO nanorods were synthesized as described earlier using a two-step process consisting of seeding and hydrothermal growth. 17 Briefly, the seed layer was deposited by an aqueous solÀgel method onto patterned ITO (15 Ω/sq, Every Rich Enterprise Limited). To improve the wettability of the substrate for the aqueous precursor solution, the wet cleaning was followed by a 15 min UVÀozone treatment before spin coating.…”