Improvement of the Optoelectrical Properties of a Transparent Conductive Polymer via the Introduction of ITO Nanoparticles and Its Application in Crystalline Silicon/Organic Heterojunction Solar Cells

Abstract

Compared with conventional transparent conductive indium tin oxide (ITO) films, poly­(3,4-ethylenedioxythiophene):poly (styrenesulfonic acid) (PEDOT:PSS) as a conductive polymer material has been diffusely applied in organic optoelectronic devices. However, its optoelectrical properties need to be further improved. Therefore, a simple and universal approach with introducing ITO nanoparticles (NPs) was proposed to improve the optoelectrical properties of PEDOT:PSS thin films. The results show that the vertical conductivity (σDC⊥) and average transmittance (from 300 to 1200 nm) of PEDOT:PSS films were enhanced about 26.8 and 6.3%, respectively. Crystalline silicon (c-Si)/organic heterojunction solar cells (HSCs) with PEDOT:PSS/ITO NP hybrid films were fabricated and performances led to further improvement. The spatial distributions of relative electrical field intensity and the carrier generation rate of the HSCs under the standard AM 1.5 G condition were simulated, which were in good agreement with the experimental conclusions.

Optimization of SiO 2 –TiO 2 nanocomposite in hole‐transporting layer (PEDOT:PSS) for enhanced performance of planar Si‐based hybrid solar cells

“…The log J‐V characteristics in the dark show an almost similar trend for all devices, depicting that the addition of NPs did not have much effect on diode quality. This is because only an optimum amount of NPs was embedded in the HTL so that the overall quality of the device does not deteriorate 31 . Rewriting Equation () can simplify and explain the relationship and change between V OC , J SC , and J 0 , such as, Equation () shows that a small change in J SC or J 0 can affect the V OC .…”

“…Figure 6B shows a possible charge transport mechanism through the fabricated hybrid solar cell considering a Schottky junction 31,62 . The photons pass through the highly transparent PEDOT:PSS organic layer and are absorbed in n‐Si, which as a result generates electron–hole pairs.…”

“…After this, for 20 minutes, the solution was stirred in an ultrasonic bath and then filtered with a PES membrane. For the embedment of the prepared SiO 2 –TiO 2 NC in the organic layer, the filtered solution was mixed with 1 wt% amount of NC because a higher amount would deteriorate the hole‐transporting layer (HTL), while a lower amount would not have full effect 31,36,37,47 . The mixture was first stirred in an ultrasonic bath for 20 minutes and then with a probe sonicator for 40 seconds for proper dispersion of the NC.…”

“…The mixture was first stirred in an ultrasonic bath for 20 minutes and then with a probe sonicator for 40 seconds for proper dispersion of the NC. The obtained mixture was finally spin‐coated on Si wafers at 2000 rpm for 60 seconds to obtain a film thickness between 150 and 200 nm 31 . After this, annealing of the prepared sample on a hot plate was done for 20 minutes at 110°C to remove all the remnants forming a highly conductive p‐type layer.…”

“…Some of these materials increase the efficiency of the cell by enhancing the J SC , while others do this by boosting the V OC. 27‐31 …”