(Photo‐)conduction measurements during the growth of evaporated bulk heterojunctions of a subphthalocyanine donor and a perfluorinated phthalocyanine acceptor

Abstract

Mixed thin films of donor‐ and acceptor‐type molecular semiconductors were prepared by physical vapour deposition and studied by conduction measurements in the dark during film growth and under illumination at three distinct wavelengths across the visible range of the solar spectrum. The molecules were chosen to provide both, good spectral coverage of the solar spectrum and appropriate differences in the electronic energy levels to allow charge carrier separation. Photocurrents were observed that indicated the expected contributions to the net photoconduction but also anomal, negative contributions were found, leading to a decreased conduction under illumination, showing the presence of isolated clusters. Ripening of the mixed films in vacuum and conditioning the films at air were studied subsequently and consequences on conduction and photoconduction discussed. The applicability of such films in evaporated organic bulk heterojunctions as photoconductors or in photovoltaic cells is discussed. Vacuum chamber for simultaneous evaporation of pure and mixed organic thin films equipped with in situ (photo)‐conduction measurements.

Charge separation in organic semiconductor blends studied by electrical in situ characterization during film growth

“…For the 97% C 60 films the current even decreases upon illumination. Such decrease has been reported for blends consisting of small amounts of SubPcBCl in F 16 PcCu upon illumination of SubPcBCl and understood by trapping of e − from F 16 PcCu in light‐induced hole states of SubPcBCl 17. The present results speak for trapping of e − from C 60 to light‐induced hole states in PcCu for films with a low content of PcCu, since the effect was one order of magnitude higher for a wavelength of 637 nm compared to 519 and 463 nm.…”

Bromido(dodecafluorosubphthalocyaninato)boron(III)

“…For examples of related halogenated boronsubphthalocyanines, see: Morse et al (2010); Paton et al (2010); Rodriguez-Morgade et al (2008); Sharman & van Lier (2005); Ros-Lis et al (2005); Fuduka et al (2002); . For applications of boronsubphthalocyanines in organic electronics, see: Mutolo et al (2006); Gommans et al (2007Gommans et al ( , 2009; Kumar et al (2009); Ma et al (2009a,b); Klaus et al (2009); Chen et al (2009Chen et al ( , 2010; Díaz et al (2007); Yasuda & Tsutsui (2007); Renshaw et al (2010). For van der Waals radii, see: Bondi (1964).…”

“…Boronsubphthalocyanine (BsubPc), a lower analogue of phthalocyanine, is of interest to researchers in the field of organic electronics (Morse et al, 2010;Mutolo et al 2006;Gommans et al 2007;Gommans et al 2009;Kumar et al 2009;Ma et al 2009a;Klaus et al 2009;Ma et al 2009b;Chen et al 2010;Chen et al 2009;Díaz et al 2007;Yasuda et al 2007;and Renshaw et al 2010). We have synthesized the title compound as it is a precursor to fluorinated phenoxy-BsubPcs (Morse et al 2010;Paton et al 2010).…”

Influence of X-ray irradiation on the optical properties of ruthenium(II)octa-(n-hexyl)-phthalocyanine thin film

“…Among the wide range of organic semiconductors considered, metal phthalocyanines (Pcs) with excellent growth properties with chemical and thermal stability, are one of the most promising candidates for the production of the majority of modern optoelectronic devices [4]. These have been exploited in modern optoelectronic devices such as photoconductors [5] and also as active components in organic electronic devices [6] like organic light-emitting diodes [7], organic field effect transistors [8,9] and organic photovoltaic cells [3]. Extensive work has been carried out on numerous metal phthalocyanines [2,10], ruthenium phthalocayanine (RuPc), which tends to be a promising compound due to its chemical-physical behaviour, it remains largely unexplored in these areas [11].…”

“…This leads to increase the possibility of implementing innovative applications in many adjacent disciplines such as nanotechnology, sensors and photonics [1][2][3]. Among the wide range of organic semiconductors considered, metal phthalocyanines (Pcs) with excellent growth properties with chemical and thermal stability, are one of the most promising candidates for the production of the majority of modern optoelectronic devices [4].…”