Solar Cells with Enhanced Photocurrent Efficiencies Using Oligoaniline‐Crosslinked Au/CdS Nanoparticles Arrays on Electrodes

Abstract

Different configurations of CdS nanoparticles (NPs) are linked to Au electrodes by electropolymerization of thioaniline‐functionalized CdS NPs onto thioaniline‐functionalized Au‐electrodes. In one configuration, thioaniline‐functionalized CdS NPs are electropolymerized in the presence of thioanline‐modified Au NPs to yield an oligoaniline‐crosslinked CdS/Au NPs array. The NP‐functionalized electrode generates a photocurrent with a quantum yield that corresponds to ca. 9%. The photocurrent intensities are controlled by the potential applied on the electrode, and the redox‐state of the oligoaniline bridge. In the oxidized quinoide state of the oligoaniline units, the bridges act as electron acceptors that trap the conduction‐band electrons that are transported to the electrode and lead to high quantum yield photocurrents. The reduced π‐donor oligoaniline bridges act as π‐donor sites that associate N,N′‐dimethyl‐4,4′‐bipyridinium, MV2+, by donor/acceptor interactions, Ka = 5270 M−1. The associated MV2+ acts as an effective trap of the conduction‐band electrons, and in the presence of triethanolamine (TEOA) as an electron donor, high photocurrent values are measured (ca. 12% quantum yield). The electropolymerization of thioaniline‐functionalized Au NPs and thioaniline‐modified CdS NPs in the presence of MV2+ yields a MV2+‐imprinted NP array. The imprinted array exhibits enhanced affinities toward the association of MV2+ to the oligoaniline π‐donor sites, Ka = 2.29 × 104 M−1. This results in the effective trapping of the conduction‐band electrons and an enhanced quantum yield of the photocurrent, ca. 34%. The sacrificial electron donor, TEOA, was substituted with the reversible donor I3−. A solar cell consisting of the imprinted CdS/Au NPs array, with MV2+ and I3−, was constructed. The cell generated a photocurrent with a quantum yield of 4.7%.

The role of (photo)electrochemistry in the rational design of hybrid conducting polymer/semiconductor assemblies: From fundamental concepts to practical applications

“…Interestingly even ternary hybrids were realized through this approach by adding either gold NPs [62] or carbon nanotubes (CNTs) [63] to the CdS/PANI system. Importantly, these hybrids showed improved photoelectrochemical properties compared with its CNT-, and Au free counterpart due to better charge separation and charge carrier collection.…”

Fabrication of hybrid solar cells using poly(2,5-dimethoxyaniline) hexagonal structures and zinc oxide nanorods

“…Although a low PCE is obtained for the PDMA:C 60 device, however it has a higher I sc and FF as compared to the PDMA:ZnO device. It is known that C 60 is a stronger electron acceptor material than ZnO, and is more efficient in charge separation which may lead to enhancement of the photocurrent [22,23]. It has also been shown that the increase in the photon harvesting from the solar spectrum results in a higher photocurrent [5,8].…”

Self-organized CdS microstructures by anodization of Cd in chloride containing Na2S solution

“…Among various semiconductors, II-VI semiconducting materials, especially the cadmium chalcogenides such as CdTe, CdSe and CdS, have received a great attention, primarily because these materials can be applied for commercial solar cells and similar photo-electrochemical devices [6][7][8][9]. Recently, CdS is particularly popular because CdS has a direct band gap of ca.…”