Route to enhance the efficiency of organic photovoltaic solar cells - by adding ferroelectric nanoparticles to P3HT/PCBM admixture

Abstract

We have demonstrated that by adding ferroelectric nanoparticles to poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) photovoltaic devices the relative efficiency can be increased compared to the same blend without these nanoparticles. In this work samples of 20 mg/ml concentrations of P3HT and PCBM were prepared in a 1:1 ratio and the samples prepared using ferroelectric barium titanate (BT) and strontium titanate (ST) nanoparticles in a 1:1:0.5 ratio. The samples were spin coated onto ITO coated glass with a layer of poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT:PSS). A top electrode of aluminium 1 cm 2 was deposited. The current-voltage characteristics of the devices were determined using a solar simulator and the absorption characteristics by UV-Vis spectroscopy. The samples with BT and ST exhibited increased absorption around 490 nm and increased open circuit voltage and short circuit current compared to the control P3HT/PCBM sample. The possible mechanism that helps to understand the increase in open circuit voltage and short circuit current is also proposed in this work.

Capacitive-like photovoltaic epiretinal stimulation enhances and narrows the network-mediated activity of retinal ganglion cells by recruiting the lateral inhibitory network

“…The distribution of the voltage densities in the retina was evaluated every 5 µm from the retinal surface. For each material, the conductivity (S m −1 ) and relative permittivity values were set to: titanium (2.6 × 10 6 /1) [68], poly(3-hexylthiophene-2,5-diyl): [6,6]-phenyl-C61-butyric acid methyl ester (0.1/3.4) [69,70], poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (30/3) [71,72], saline (1/80) [73,74], polydimethylsiloxane (PDMS) (2 × 10 −14 /2.75) [75], and retinal tissue (0.1/0.01) [76]. The voltage density was spatially approximated as a Gaussian probability distribution and temporally fitted as a first-degree exponential peaking at the FEA output values.…”