Poly(Styrene Sulfonate) Free Poly(3,4-Ethylenedioxythiophene) as a Robust and Solution-Processable Hole Transport Layer for Organic Solar Cells

Abstract

We first time report poly(styrene sulfonate) (PSS) free poly(3,4ethylenedioxythiophene) (PEDOT) as a novel solution-processable hole transport layer (HTL) for organic solar cells. The transparent and conducting PEDOT thin film was obtained by solid state polymerization (SSP) of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) on ITO coated glass substrate (by heating of the monomer at 60 8C for overnight). The thicknesses of the obtained thin films were optimized by using different concentrations of DBEDOT in chlorobenzene during spin coating. Two different combinations of active layers such as poly(3-hexylthiophene):phenyl-C 61 -butyric acid methyl ester (P3HT:PC 61 BM) and poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]:phenyl-C 71 -butyric acid methyl ester (PCDTBT:PC 71 BM) were used for device fabrication. Power conversion efficiencies were achieved up to 0.71 % and 1.70 % in a simple geometry of ITO/ssp-PEDOT/active layer/Al under ambient conditions. The potential importances of the ssp-PEDOT as an HTL are robust, stable, PSS free and solution-processable for organic solar cells.

The damaging effects of the acidity in PEDOT:PSS on semiconductor device performance and solutions based on non-acidic alternatives

“…The concept of polymerising an EDOT-based monomer on the substrate was further developed by Patra et al 51 to be compatible with solution-processing. In this study, 2,5-dibromo-3,4-ethylenedioxythiophene was deposited onto ITO substrates by spin-coating from a chlorobenzene solution and the monomer underwent solid-state polymerisation by heating the film overnight at 60 1C.…”

Donor−acceptor−donor (D-A-D) structural monomers as donor materials in polymer solar cells: a DFT/TDDFT approach

“…Conjugated polymers have sparked significant interest in recent decades [ 12 , 13 ] due to their potential applications in fields such as organic field-effect transistors [ 14 ], organic light-emitting diodes [ 15 ], electrochromic devices [ 16 ], photovoltaics [ 17 ], electronic displays, supercapacitors, thermoelectric devices [ 18 ], and so on.…”

Poly(3,4-ethylenedioxyselenophene): effect of solvent and electrolyte on electrodeposition, optoelectronic and electrochromic properties

“…Indeed, the good electrochemical and thermal stability of PEDOT, moderate band gap (1.6 eV), high optical transparency in the doped state, high electrical conductivity and low oxidation potential have resulted in its widespread application in variety of electronic and optoelectronic devices. 17,18 Recently, two dimensional polymers and materials have emerged as promising candidate for designing of multifunctional materials with better electronic and optoelectronic properties. 19 In contrast to polythiophene and PEDOT, their selenium analogue have drawn attention only in recent years 20,21 despite possessing better properties such as narrow band gap, low redox potential, better charge transport and higher doping.…”