Efficient and Flexible ITO‐Free Organic Solar Cells Using Highly Conductive Polymer Anodes

Abstract

ITO‐free organic solar cells are fabricated on glass and on flexible substrates. The efficiencies of these cells on glass and plastic substrates (3.27% and 2.8%, respectively) were comparable to those of ITO‐based devices (3.66% and 2.9%, respectively). Furthermore, in the flexibility test the ITO‐free cells on flexible substrates manifested superior mechanical robustness compared with ITO‐based cells.

Highly conductive and transparent carbon nanotube composite thin films deposited on polyethylene terephthalate solution dipping

“…The conventional transparent and conductive thin films, such as indium tin oxide (ITO), are brittle. When deposited on flexible substrates, the conductivity of those thin film electrodes tends to deteriorate significantly after subjecting to thermal and/or mechanical strain [1][2][3]. For instance, Na et al [1] found that the resistance of ITO on Polyethylene Terephthalate (PET), increased by ∼40 times after ∼ 2500 bending cycles at a radius of ∼8 mm.…”

“…When deposited on flexible substrates, the conductivity of those thin film electrodes tends to deteriorate significantly after subjecting to thermal and/or mechanical strain [1][2][3]. For instance, Na et al [1] found that the resistance of ITO on Polyethylene Terephthalate (PET), increased by ∼40 times after ∼ 2500 bending cycles at a radius of ∼8 mm. On the other hand, transparent carbon nanotube (CNT) conductive thin films have shown great potential in addressing this issue [4,5].…”

Universal high work function flexible anode for simplified ITO-free organic and perovskite light-emitting diodes with ultra-high efficiency

“…However, research on flexible anodes to date has been focused mainly on their electrical properties (that is, reduction of sheet resistance), and little care has been taken for their electronic properties: one of the most serious concerns is that these flexible electrodes often suffer from low work function (WF) (highly conductive polymers: 4.5-5.0 eV, [10][11][12][13][14][15][16] silver nanowires: 4.2-4.3 eV, 19 carbon nanotubes [21][22][23] /graphenes: 4,25-27 4.4-4.6 eV) that give rise to hole injection problem in optoelectronic devices. For example, solution-processed conducting polymers represented by poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) are being spotlighted as next-generation flexible and stretchable transparent electrodes.…”

Photopatternable PEDOT:PSS/PEG hybrid thin film with moisture stability and sensitivity

“…Conducting polymers (CPs) have attracted increasing attention over past decades due to their unique combinations of chemical and physical properties from metallic and polymeric materials, including mobile charged species and a flexible and tunable matrix [1][2][3][4][5][6][7][8][9][10][11][12] . Compared with carbon-based nanomaterials, for example, carbon nanotubes, graphene, and nanowires, CPs offer higher flexibility and greater tunability in the material properties 3,4 .…”