Nanostructured Photovoltaic Cells Fabricated with PAO (Porous - - PowerPoint PPT Presentation

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Nanostructured Photovoltaic Cells Fabricated with PAO (Porous Aluminum Oxide) Templates

Lin Li

(Mechanical Engineering) Santa Barbara City College Lab Mentor: Martin Schierhorn Faculty Advisors: Galen D. Stucky Martin Moskovits Department of Chemistry & Biochemistry, UCSB Funding: The Institute for Collaborative Biotechnologies (ICB)

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Application of Nanostructured Photovoltaic Cells Fabricated with PAO Templates

• 1. Energy Source:

solar power (free and renewable)

• 2. Development of

Materials: flexible, cost- effective, easily processable (such as polymers)

(Interface of two different materials)

• The diagram of

the nanostructured photovoltaic cells

Photons

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Procedure of Making CdSe Cells

1 5 2 3 6 4 V

PAO Metal layer CdSe Nanorods Copper Strip

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Goals

Find optimal thickness of TiO2 Try out different metal layers instead of gold (Ti or Ni) Play around with different dimensions

• f nanorodes

Increase the absorption of photons decreased recombination kinetics limit the Schottky barrier issues

1 5 2 3 6 4 V

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Preparation of PAO Templates

• First Anodization

1. Condition:

• -- 0.3 M oxalic acid
• -- 15 degree C
• -- 40 Volts for 3 hours
• 2. Removed with H3PO4 /

H2CrO4 at 65 degree C for 2 hours (in the oven)

• Second Anodization

1. Same conditions for 12 hours

• -- results: pores of ~80

micrometers long by ~40 nm in diameter

Template after 2nd Anodization

1 2

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CdSe Nanorods under the SEM

CdSe nanorods TiO2 layer Metal layer (ITO layer)

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V

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Electrochemical Photovoltaic Characteristics of CdSe

CdSe samples Efficiency = ( Voc * Isc * FF )

( 100mW/cm2 )

• Voc – open circuit voltage
• Isc – short circuit current
• FF – fill factor

Keithley SMU

Equipment for testing

• 0.3
• 0.2
• 0.1

0.0

• 15.0µ
• 10.0µ
• 5.0µ

0.0 5.0µ 10.0µ 15.0µ Current (A) Potential (V) vs. Pt

with TiO2 + Au Au with TiO2 + ITO

IV characteristics Voc Voc Isc Isc

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Summary

• Conclusions

1. IV Curve shows that TiO2 layer leads to better efficiency than the one without it 2. TiO2 layer decreases recombination kinetics

• Future Plans

1. Combine P3HT polymer with CdSe half solar cells

• 2. Substitute with new polymers
• Picture comes from:

Picture comes from: www.bee.qut.edu.au/.../projects/photovoltaics

P3HT polymer

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Acknowledgements

• Mentor: Martin Schierhorn
• Adviser: Galen D. Stucky

Martin Moskovits

• Professors: Nick Arnold

& Dr. Young

• Funding Source: The Institute for

Collaborative Biotechnologies (ICB)

• Summer research program: INSET

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THANK YOU !

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Diagrams of Anodization

Equipment for Anodization

2 4 6 8 10 12 2 4 6 8 10 12 14 16 18 0.10 0.11 0.12 0.13 Current (A) Temperature (C) tim e (h) Tem p 2nd Anodization 5_16 current

Time vs. Temperature & Time vs. Current

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PAO Templates

(With gold layer) (With ITO layer)

• PAO Templates