Effects of Mg Content on Zn1-xMgxO:Al Transparent Conducting Films

AbstractConductive zinc oxide (ZnO) films are used extensively as transparent electrodes in thin-film photovoltaic solar cells. Compared with the widely used indium tin oxide (ITO) and tin oxide (SnO2), ZnO has a smaller optical bandgap. ZnO is commonly used as a front contact for copper indium gallium diselenide (CIGS) solar cells, but it forms a small, unfavorable conduction-band offset with the CdS layer. The optical bandgap of ZnO could easily be engineering by alloying with MgO or CdO. In this work, we try to optimize the ZnO for CIGS solar cells. The optical and electrical properties of Zn1-xMgxO:Al films fabricated by co-sputtering were studied. Two targets: ZnO:Al and MgO, were used. The ratio of ZnO/MgO was varied continuously on the 6”x6” glass substrate, and the effects of composition on the properties of the Zn1-xMgxO:Al films were investigated. The carrier concentration and mobility of the Zn1-xMgxO:Al films decreased quickly with increasing Mg content. However, the optical properties of the Zn1-xMgxO:Al films do not vary linearly with Mg content, as reported by most papers. The observed optical bandgap of Zn1-xMgxO:Al films is actually first narrowed, then increased with the Mg content. The shift in optical bandgap from narrow to wide occurs at around a composition of x = 0.07. After the point of x = 0.07, the bandgap width star increase but film sheet resistance already too low. Our result therefore suggests that the alloyed Zn1-xMgxO:Al does not benefit the CIGS solar cell.

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Improving Performance of CIGS Solar Cells by Annealing ITO Thin Films Electrodes

International Journal of Photoenergy ◽

10.1155/2015/483147 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Chuan Lung Chuang ◽

Ming Wei Chang ◽

Nien Po Chen ◽

Chung Chiang Pan ◽

Chung Ping Liu

Keyword(s):

Thin Films ◽

Optical Properties ◽

Solar Cells ◽

Indium Tin Oxide ◽

Copper Indium Gallium Diselenide ◽

Glass Substrates ◽

Ito Film ◽

Ito Thin Films ◽

Cigs Solar Cells ◽

Ito Films

Indium tin oxide (ITO) thin films were grown on glass substrates by direct current (DC) reactive magnetron sputtering at room temperature. Annealing at the optimal temperature can considerably improve the composition, structure, optical properties, and electrical properties of the ITO film. An ITO sample with a favorable crystalline structure was obtained by annealing in fixed oxygen/argon ratio of 0.03 at 400°C for 30 min. The carrier concentration, mobility, resistivity, band gap, transmission in the visible-light region, and transmission in the near-IR regions of the ITO sample were-1.6E+20 cm−3,2.7E+01 cm2/Vs,1.4E-03 Ohm-cm, 3.2 eV, 89.1%, and 94.7%, respectively. Thus, annealing improved the average transmissions (400–1200 nm) of the ITO film by 16.36%. Moreover, annealing a copper-indium-gallium-diselenide (CIGS) solar cell at 400°C for 30 min in air improved its efficiency by 18.75%. The characteristics of annealing ITO films importantly affect the structural, morphological, electrical, and optical properties of ITO films that are used in solar cells.

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Degradation Mechanism Due to Water Ingress Effect on the Top Contact of Cu(In,Ga)Se2 Solar Cells

Energies ◽

10.3390/en13174545 ◽

2020 ◽

Vol 13 (17) ◽

pp. 4545

Author(s):

Deewakar Poudel ◽

Shankar Karki ◽

Benjamin Belfore ◽

Grace Rajan ◽

Sushma Swaraj Atluri ◽

...

Keyword(s):

Solar Cells ◽

Indium Tin Oxide ◽

Degradation Mechanism ◽

Transparent Conductive Oxide ◽

Window Layer ◽

Copper Indium Gallium Diselenide ◽

Copper Indium ◽

Cigs Solar Cells ◽

The Impact ◽

Secondary Ion

The impact of moisture ingress on the surface of copper indium gallium diselenide (CIGS) solar cells was studied. While industry-scale modules are encapsulated in specialized polymers and glass, over time, the glass can break and the encapsulant can degrade. During such conditions, water can potentially degrade the interior layers and decrease performance. The first layer the water will come in contact with is the transparent conductive oxide (TCO) layer. To simulate the impact of this moisture ingress, complete devices were immersed in deionized water. To identify the potential sources of degradation, a common window layer for CIGS devices—a bilayer of intrinsic zinc oxide (i-ZnO) and conductive indium tin oxide (ITO)—was deposited. The thin films were then analyzed both pre and post water soaking. To determine the extent of ingress, dynamic secondary ion mass spectroscopy (SIMS) was performed on completed devices to analyze impurity diffusion (predominantly sodium and potassium) in the devices. The results were compared to device measurements, and indicated a degradation of device efficiency (mostly fill factor, contrary to previous studies), potentially due to a modification of the alkali profile.

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Indium tin oxide with titanium doping for transparent conductive film application on CIGS solar cells

Applied Surface Science ◽

10.1016/j.apsusc.2015.02.130 ◽

2015 ◽

Vol 354 ◽

pp. 31-35 ◽

Cited By ~ 13

Author(s):

Wei-Sheng Liu ◽

Huai-Ming Cheng ◽

Hung-Chun Hu ◽

Ying-Tse Li ◽

Shi-Da Huang ◽

...

Keyword(s):

Solar Cells ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Transparent Conductive Film ◽

Titanium Doping ◽

Conductive Film ◽

Cigs Solar Cells

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Dye-sensitized solar cells based on indium-tin oxide nanowires coated with titania layers

2008 Conference on Optoelectronic and Microelectronic Materials and Devices ◽

10.1109/commad.2008.4802129 ◽

2008 ◽

Author(s):

Hong-Wen Wang ◽

Chi-Feng Ting ◽

Miao-Ken Hung ◽

Chwei-Huann Chiou ◽

Ying-Ling Liu ◽

...

Keyword(s):

Solar Cells ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Dye Sensitized Solar Cells ◽

Oxide Nanowires ◽

Dye Sensitized ◽

Sensitized Solar Cells

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Contact resistance of indium tin oxide and fluorine-doped indium oxide films grown by ultrasonic spray pyrolysis to diffusion layers in silicon solar cells

Solar Energy Materials and Solar Cells ◽

10.1016/j.solmat.2015.01.018 ◽

2015 ◽

Vol 137 ◽

pp. 26-33 ◽

Cited By ~ 20

Author(s):

G.G. Untila ◽

T.N. Kost ◽

A.B. Chebotareva ◽

E.D. Kireeva

Keyword(s):

Solar Cells ◽

Contact Resistance ◽

Spray Pyrolysis ◽

Indium Oxide ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Ultrasonic Spray Pyrolysis ◽

Silicon Solar Cells ◽

Diffusion Layers ◽

Ultrasonic Spray

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Ag Doped Zinc Tin Oxide as Cathode for Organic Photovoltaic Cells

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.209-211.1719 ◽

2012 ◽

Vol 209-211 ◽

pp. 1719-1722

Author(s):

Ming Guo Zhang ◽

Nan Hai Sun

Keyword(s):

Solar Cells ◽

Tin Oxide ◽

Organic Solar Cells ◽

Indium Tin Oxide ◽

Bulk Heterojunction ◽

Indium Tin Oxide Electrode ◽

Heterojunction Solar Cells ◽

Visible Part ◽

Cell Architecture ◽

Zinc Tin Oxide

A thin Ag layer embedded between layers of zinc tin oxide (ZTO) are compared to cells using an indium tin oxide electrode was investigated for inverted organic bulk heterojunction solar cells employing a multilayer electrode. ZTO/Ag/ ZTO (ZAZ) electrode is the preparation at room temperature, a high transparency in the visible part of the spectrum, and a very low sheet resistance comparable to treated ITO without the need for any thermal post deposition treatment as it is necessary for ITO. The In-free ZAZ electrodes exhibit a favorable work function of 4.3 eV and are shown to allow for excellent electron extraction even without a further interlayer. This renders ZAZ a perfectly suited bottom electrode for inverted organic solar cells with simplified cell architecture.

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