Organic solar cells with carbon nanotubes replacing In2O3:Sn as the transparent electrode

Abstract

We report two viable organic excitonic solar cell structures where the conventional In2O3:Sn (ITO) hole-collecting electrode was replaced by a thin single-walled carbon nanotube layer. The first structure includes poly(3,4-ethylenedioxythiophene) (PEDOT) and gave a nonoptimized device efficiency of 1.5%. The second did not use PEDOT as a hole selective contact and had an efficiency of 0.47%. The strong rectifying behavior of the device shows that nanotubes are selective for holes and are not efficient recombination sites. The reported excitonic solar cell, produced without ITO and PEDOT, is an important step towards a fully printable solar cell.

Transverse charge transport in inkjet printed poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)

“…PEDOT:PSS (poly (3,4-ethylenedioxythiophene) polystyrene sulfonate) is a popular conductive polymer, used as a hole transport layer in organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs) [1][2][3][4][5][6] given its high workfunction, reaching 5.2 eV, and high conductivity, reaching 130 S cm -1 in in-plane charge transport [7][8][9]. In all such applications, conduction takes place in the transverse, z, direction while the value of the workfunction of each conductive layer or active material is most important to maintain the continuous charge flow in the electron and hole transport, respectively.…”

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

“…In addition to its flexibility, CNT films also show high transparency in a large range of solar spectrum as compared to ITO which has excellent transparency in the visible range. In recent years, transparent CNT thin films have been studied and tested in a variety of optoelectronic devices [6][7][8][9][10].…”

Low temperature synthesis of multiwalled carbon nanotubes and incorporation into an organic solar cell

“…Therefore, the good conductivity MWCNT is responsible for the improved electrical conductance due to their internal walls participating in the electrical transportation which enables large current-carrying capacity [24]. Preventive procedures of making the devices in a dark room were executed such that the PEDOT:PSS would not degrade [62]. This was so because when exposed to UV illumination the PEDOT:PSS disintegrates and initiates water into the active layer of the device and thus making it being slightly acidic.…”