Improved CdTe Solar-Cell Performance by Plasma Cleaning the TCO Layer

Swanson, Drew E.; Geisthardt, Russell M.; McGoffin, J. Tyler; Williams, John D.; Sites, James R.

doi:10.1109/jphotov.2013.2244163

Cited by 36 publications

(14 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This effect has been optimized using an SnO 2 ‐based material that can be deposited in a float glass manufacturing line . A similar approach uses surface modification of the TCO . Using the thinnest possible CdS layer requires a compromise between current collection and other device parameters for highest efficiency.…”

Section: Introductionmentioning

confidence: 99%

Optimization of CdTe thin‐film solar cell efficiency using a sputtered, oxygenated CdS window layer

Kephart

Geisthardt

Sampath

2015

Progress in Photovoltaics

Self Cite

View full text Add to dashboard Cite

A major source of loss in cadmium sulfide/cadmium telluride (CdS/CdTe) solar cells results from light absorbed in the CdS window layer, which is not converted to electrical current. This film can be made more transparent by oxygen incorporation during sputter deposition at ambient temperature. Prior to this work, this material has not produced high-efficiency devices on tin oxide-coated soda-lime-glass substrates used industrially. Numerous devices were fabricated over a variety of process conditions to produce an optimized device. Although the material does not show a consistent increase in band gap with oxygenation, absorption in this layer can be virtually eliminated over the relevant spectrum, leading to an increase in short-circuit current. Meanwhile, fill factor is maintained, and open-circuit voltage increases relative to baseline devices with sublimated CdS. The trend of device parameters with oxygenation and thickness is consistent with an increasing conduction band offset at the window/CdTe interface. Optimization considering both initial efficiency and stability resulted in a National Renewable Energy Laboratory verified 15.2%-efficient cell on 3.2-mm soda-lime glass. This window material was shown to be compatible with SnO 2 -based transparent conducting oxide and high resistance transparent coated substrates using in-line compatible processes.

show abstract

Section: Introductionmentioning

confidence: 99%

Optimization of CdTe thin‐film solar cell efficiency using a sputtered, oxygenated CdS window layer

Kephart

Geisthardt

Sampath

2015

Progress in Photovoltaics

Self Cite

View full text Add to dashboard Cite

show abstract

“…A thin layer of n-type CdS, ,100 nm, and a thicker p-type layer (y2?5 mm) of CdTe was deposited by closed space sublimation to form the absorber layer. 8 The device then received a copper doping treatment which promotes the formation of an Ohmic contact with a metallic electrode. The cells were then sent to the Centre for Renewable Systems and Technology (CREST) at Loughborough University for the deposition of a sputtered gold back contact.…”

Section: Methodsmentioning

confidence: 99%

Inkjet and laser hybrid processing for series interconnection of thin film photovoltaics

Crozier

Brunton

Henley

et al. 2014

Materials Research Innovations

View full text Add to dashboard Cite

Inkjet deposition can be a complementary technology to laser ablation to enable new processes. One such process is the One step interconnect for thin film photovoltaics, which is an improved method for series interconnection. The standard series interconnection process consists of three laser scribes between the deposition of the three key cell layers; transparent front contact, absorber layer and the metallic back contact. The one step interconnect allows the series interconnection to occur after the deposition of all layers significantly simplifying the manufacturing process. This is achieved by inkjet printing of conductive and insulative materials concurrently with depth selective laser scribes. The one step interconnect process has been shown to make effective interconnects on cadmium telluride photovoltaics with fill factors .60%. The benefits are many and include the reduction of capital equipment costs, reduced panel wastage and potentially improved material performance. The process is fully scalable and production ready.

show abstract

“…Plasma cleaning has recently demonstrated the capability of depositing more uniform CdS window layers (compared to standard wet cleaning methods) with greatly reduced pin-hole defects, improving the V oc of CdS/CdTe solar cells [18,19]. The V oc improvement is due to prevention of low photovoltage CdTe/TCO interfaces forming locally.…”

Section: Cdte Pv Devices On Cover Glassmentioning

confidence: 99%