EE 237: Solar Energy Conversion Week 6: MJ solar cell – wrap up ...

EE 237: Solar Energy Conversion Week 6:

MJ solar cell – wrap up Recombination Physics of amorphous materials May 6th 2013 tanford University

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Concentrators

tanford University

EE 237 : Aneesh Nainani

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Concentrators

tanford University

EE 237 : Aneesh Nainani

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Concentrators

tanford University

EE 237 : Aneesh Nainani

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Suggested Reading • III-V MJ solar cells • Handbook of Photovoltaics, Chapter 8 • http://bit.ly/XPtTQg • HO7#: Book chapter on III-V MJ solar cell • Concentrator design • Handbook of Photovoltaics, Chapter 10 • http://bit.ly/115DsyO

tanford University

EE 237 : Aneesh Nainani

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Quiz: MJ cell

Light

p-type

n-type material

material

(small Eg)

(large Eg)

New scheme: 2 materials, 1 junction, is it as good as having 2 junctions ? tanford University

EE 237 : Aneesh Nainani

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Quiz: MJ cell

p-type Light

material

(large Eg)

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n-type material (small Eg)

EE 237 : Aneesh Nainani

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Recombination

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EE 237 : Aneesh Nainani

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Quiz: Recombination mechanisms in bulk

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EE 237 : Aneesh Nainani

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RG lifetime

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EE 237 : Aneesh Nainani

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c-Si bulk recombination

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EE 237 : Aneesh Nainani

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P-Si recombination lifetime

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EE 237 : Aneesh Nainani

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Bulk lifetime

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EE 237 : Aneesh Nainani

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Carrier lifetime measurements

σ tanford University

EE 237 : Aneesh Nainani

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Instrumentation

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EE 237 : Aneesh Nainani

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Instrumentation

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EE 237 : Aneesh Nainani

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tanford University

EE 237 : Aneesh Nainani

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tanford University

EE 237 : Aneesh Nainani

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Measuring SRV

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EE 237 : Aneesh Nainani

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Measuring SRV

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EE 237 : Aneesh Nainani

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Surface recombination velocity

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EE 237 : Aneesh Nainani

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How important is SRV ?

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EE 237 : Aneesh Nainani

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Preventing Surface Recombination ?

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EE 237 : Aneesh Nainani

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tanford University

EE 237 : Aneesh Nainani

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Physics of amorphous materials

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EE 237 : Aneesh Nainani

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Quiz: should amorphous materials have a bandgap?

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EE 237 : Aneesh Nainani

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What's the origin of bandgap in amorphous materials ?

Continuous Random Network

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Continuous Random Network

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Short Range and Long Ranger Order

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EE 237 : Aneesh Nainani

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Localized and Extended States

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Continuous Random Network

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Density of States

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Density of States

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Defects in CRN model

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Defects states

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Single electron representation of amphoteric bonds

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EE 237 : Aneesh Nainani

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Recombination Generation

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SRH R/G statistics (Tail States)

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EE 237 : Aneesh Nainani

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Sah-Shockley R/G statistics (Dangling Bonds)

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EE 237 : Aneesh Nainani

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Most important change: In way of thinking

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Most important change: In way of thinking

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