The Effect of the Indium(III) Phthalocyanine Chloride Films on the Behavior of Flexible Devices of Flat and Disperse Heterojunction

María Elena Sánchez-Vergara,Paulina Smith-Ruiz,Citlalli Rios,Roberto Salcedo,Raquel Carrera-Téllez

doi:10.3390/coatings9100673

María Elena Sánchez-Vergara, Paulina Smith-Ruiz + Show 3 more

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https://doi.org/10.3390/coatings9100673

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Abstract

By means of flat-heterojunction structures based on small semiconductor molecules (MSCs), an analysis of the indium(III) phthalocyanine chloride (In(III)PcCl) film as a constituent of optoelectronic devices was performed. The study included the behavior of In(III)PcCl playing three different roles: a donor species, an electronic acceptor, and a hole layer carrier. The flat-heterojunction structures were prepared by vacuum deposition method that permits a controlled layer-by-layer growth of high purity films. The investigated structures were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), UV-vis spectroscopy and optical bandgaps were obtained by Tauc’s and Cody’s methods. As the structures exhibit a large spectral absorption in the visible range, they were incorporated into flat-heterojunction devices based on flexible and rigid substrates. However, during the synthesis of those structures, the disperse heterojunction arrangement was found and indeed it showed to be more efficient than the initial flat-heterojunction. In order to complement these results, disperse heterojunction arrangement structure as well as its bandgap value were obtained by DFT calculations. Finally, the electronic behavior of both fabricated devices, disperse heterojunction and flat-heterojunction were compared.

Highlights

The material requirements for the most basic architecture of organic electronic devices include a transparent substrate, a transparent electrode, a light-absorbing organic active layer, and a counter-electrode
The analysis of the In(III)PcCl film as a constituent of optoelectronic devices took place in two parts. (i) During the first part of the study, three flat heterojunction (FHJ) systems, denominated S1, S2 and S3 were manufactured. In those arrangements the In(III)PcCl was studied as hole transporter layer (HTL), as an acceptor and as a donor species respectively
These systems were optoelectronically characterized through the fabrication of the devices D1, D2 and D3. (ii) During the second part of the study, the donor-acceptor species of the active layer with higher optoelectronic properties obtained in the previous stage were analyzed by DFT in order to obtain a bulk heterojunction (BHJ) structure more efficient than the FHJ

Summary

Introduction

The material requirements for the most basic architecture of organic electronic devices include a transparent substrate, a transparent electrode, a light-absorbing organic active layer, and a counter-electrode. Glass is the substrate most frequently employed because it is cheap and it provides a barrier against oxygen and water diffusion into the device [1]. The use of flexible substrates, for example polyethylene terephthalate (PET), has been recently considered giving rise to flexible electronics included in new technologies. Devices based on flexible substrates can be ultrathin and comprise the characteristic of adapting to different surfaces. Forrest et al has demonstrated that it is possible the manufacture of organic light emitting diodes (OLED) on polymeric substrates [4]

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