Amorphous Silicon based Solar Cell Technologies: Status, Challenges, and Opportunities

MRS Proceedings ◽

10.1557/proc-808-a7.5 ◽

2004 ◽

Vol 808 ◽

Cited By ~ 3

Author(s):

Rajeewa R. Arya

Keyword(s):

Solar Cell ◽

Amorphous Silicon ◽

Commercial Application ◽

Amorphous Silicon Solar Cell ◽

Building Integrated Photovoltaic ◽

Photovoltaic Applications ◽

Challenges And Opportunities ◽

Module Development ◽

Silicon Based ◽

Conversion Efficiencies

ABSTRACTAdvances in amorphous silicon solar cell and module development over the past two decades has led to widespread commercial application in consumer and building integrated photovoltaic applications (BIPV). The technology has taken two pathways: (i) superstrate and (ii) substrate. Both pathways have unique advantages over crystalline modules and have demonstrated promising stability and reliability with continuous improvement in performance. Multi-junction modules with amorphous and microcrystalline silicon have demonstrated initial conversion efficiencies in the range of 13%-13.5%.

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Development of transparent conductive oxide materials for improved back reflector performance for amorphous silicon based solar cells

MRS Proceedings ◽

10.1557/proc-808-a9.44 ◽

2004 ◽

Vol 808 ◽

Cited By ~ 3

Author(s):

Scott J. Jones ◽

David Tsu ◽

Tongyu Liu ◽

Jeff Steele ◽

Rey Capangpangan ◽

...

Keyword(s):

Solar Cell ◽

Structural Analysis ◽

Amorphous Silicon ◽

Transparent Conductive Oxide ◽

Oxide Materials ◽

Conductive Oxide ◽

Back Reflector ◽

Silicon Based ◽

Conversion Efficiencies ◽

Substrate Temperatures

ABSTRACTA new back reflector comprised of an Al/(multi-layered stack)/ZnO structure is being developed to replace Al/ZnO used in manufacturing and boost conversion efficiencies with improved back reflector performance. Use of the multi-layered stack should lead to improved reflectivity which will in turn improve solar cell currents and efficiencies. The results from studies of different transparent conductive oxides (TCOs) which comprise the multi-layered stack are reported with emphasis on ZnO alloys. Alloying with Si or MgF2 and using moderately high substrate temperatures, TCOs with low indices of refraction between 1.6 and 1.7 have been fabricated. The Si, Mg and F contents for these alloys were near 14, 12 and 33 at.%. Structural analysis demonstrates that alloys with MgF2 have smother surfaces and finer morphologies than those for ZnO. The expected high values for multi-layered structures with these alloys have yet to be achieved but this is likely due to properties of layers in the structure other than the ZnO alloys which have yet to be fully optimized.

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Use of Transparent Conductive Oxide Materials with Low Indices of Refraction in Amorphous Silicon-Based Solar Cell Technology

MRS Proceedings ◽

10.1557/proc-862-a21.1 ◽

2005 ◽

Vol 862 ◽

Author(s):

Scott J. Jones ◽

Joachim Doehler ◽

Tongyu Liu ◽

David Tsu ◽

Jeff Steele ◽

...

Keyword(s):

Solar Cell ◽

Amorphous Silicon ◽

Transparent Conductive Oxide ◽

Open Circuit ◽

Long Term Stability ◽

Back Reflectors ◽

Stability Issues ◽

Silicon Based ◽

Solar Cell Technology

AbstractNew types of transparent conductive oxides with low indices of refraction have been developed for use in optical stacks for the amorphous silicon (a-Si) solar cell and other thin film applications. The alloys are ZnO based with Si and MgF added to reduce the index of the materials through the creation of SiO2 or MgF2, with n=1.3-1.4, or the addition of voids in the materials. Alloys with 12-14% Si or Mg have indices of refraction at λ=800nm between 1.6 and 1.7. These materials are presently being used in optical stacks to enhance light scattering by Al/multi-layer/ZnO back reflectors in a-Si based solar cells to increase light absorption in the semiconductor layers and increase open circuit currents and boost device efficiencies. In contrast to Ag/ZnO back reflectors which have long term stability issues due to electromigration of Ag, these Al based back reflectors should be stable and usable in manufactured PV products. In this manuscript, structural properties for the materials will be reported as well as the performance of solar cell devices made using these new types of materials.

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