Gallium-doped zinc oxide films as transparent electrodes for organic solar cell applications

Abstract

We report microstructural characteristics and properties of gallium-doped ZnO films deposited on glass by pulsed laser deposition. The Zn0.95Ga0.05O film deposited at 200 °C and 1×10−3 Torr showed predominant ⟨0001⟩ orientation with a metallic behavior and a resistivity of 2×10−4 Ω cm at room temperature. Low resistivity of the ZnGaO films has been explained in terms of optimal combination of carrier concentration and minimized scattering, and is correlated with the microstructure and the deposition parameters. Power conversion efficiency comparable to indium tin oxide-based devices (1.25±0.05%) is achieved on a Zn0.95Ga0.05O∕Cu-phthalocyanine∕C60 double-heterojunction solar cell.

Designs and Architectures for the Next Generation of Organic Solar Cells

“…Finding alternatives to ITO is a major area of research in the last five years. Some of the alternatives are doped metal oxides [33][34][35][36][37], organic polymers [38][39][40][41][42][43], metal grids [44][45][46][47], carbon nanotubes [48][49][50][51] and graphene [52,53]. [37].…”

Zinc oxide modified with benzylphosphonic acids as transparent electrodes in regular and inverted organic solar cell structures

“…ZnO is already intensively used as a low-cost, transparent electrode in inorganic devices, 1,2 but more recently also as a charge selective interlayer material in efficient organic solar cells (OSCs) or organic light-emitting diodes (OLEDs). 3,4 However, the moderate work function (WF) of untreated ZnO of about 4.3 eV causes injection barriers to almost all conventional organic semiconductors [5][6][7][8][9] and the WF of such ZnO layers is poorly reproducible due to the physisorption of contaminations. 10 On the other hand, its poor chemical stability in an acidic environment [11][12][13] makes the modification of the ZnO WF particularly challenging.…”

Transparent conductive electrodes of mixed TiO2−x–indium tin oxide for organic photovoltaics

“…When used in organic photovoltaic devices based on bulk heterojunction photoactive layer of poly (3-hexylthiophene) and [6,6] The importance of transparent conducting oxides (TCOs) has grown due to their rapidly increasing usage in applications such as touch panels, flat panel displays, and other optoelectronic devices including photovoltaic cells, photo-detectors, wave-guides, etc. [1][2][3][4][5] Sputtered indium tin oxide (ITO) has been commonly used as TCO electrodes due to its excellent optical transparency, low resistivity, and high reliability. [6][7][8] However, indium (In) resources are dwindling due to the fact that the element cannot be mined directly in significant amounts (in most industrial cases In is a byproduct of zinc mining).…”

“…[5][6][7] Moreover, conductive polymers, carbon nanotubes (CNTs), and graphene have also been attempted as cost-effective candidates. [8][9][10] In this article, we introduce a TCO that consists of mixed structure of co-sputtered titanium dioxide (TiO 2Àx ) and ITO.…”