response of photoluminescence in photovoltaics The Student: - - PowerPoint PPT Presentation

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response of photoluminescence in photovoltaics The Student: - - PowerPoint PPT Presentation

Mar 22, 2023 225 likes •561 views

Application of the spectral response of photoluminescence in photovoltaics The Student: Mattias Juhl The Supervisors: Professor Thorsten Trupke Scientia Profesor Martin Green Photoluminescence? Luminescence: Radiative recombination of

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Application of the spectral response of photoluminescence in photovoltaics

The Student: Mattias Juhl The Supervisors: Professor Thorsten Trupke Scientia Profesor Martin Green

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  • Luminescence: Radiative

recombination of excess carriers

  • Photo  generated by light
  • Why photoluminescence?

Photoluminescence?

Conduction Band Valence Band

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SLIDE 3
  • Luminescence: Radiative

recombination of excess carriers

  • Photo  generated by light
  • Why photoluminescence?
  • How do I measure

photoluminescence?

  • What am I doing that’s new?

Photoluminescence?

  • 1. Trupke, T., et al. (2006). Applied Physics Letters, 89(4), 44107.
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SLIDE 4
  • The spectral response

determines wavelength dependent properties

  • That is a lot of Information
  • Si’s Photoluminescence only

at 900 - 1300 nm

Spectral response

Fig: Simulated EQE in PC1D[1]

1. D.A. Clugston and P.A. Basore, Conf. Rec. Twenty Sixth IEEE Photovolt. Spec. Conf.-1997

Lets change the illumination wavelength and measure photoluminescence

𝐹𝑅𝐹𝐾𝑡𝑑 =

𝐽𝑡𝑑 𝑟𝑂𝑞ℎ

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SLIDE 5

Application 1: Band-to-band absorptance

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SLIDE 6

𝐽𝑄𝑀 ∝ Δ𝑜𝑂𝑒 𝜐 =

Δ𝑜 𝐻

𝐽𝑄𝑀 ∝ 𝐻𝜐 For a constant effective lifetime 𝐽𝑄𝑀 ∝ 𝐻 ∝ 𝐵𝑂𝑞ℎ

Application 1: Band-to-band absorptance

𝐽𝑞𝑚 𝑂𝑞ℎ ∝ 𝐵

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SLIDE 7

Application 1: Band-to-band Absorptance

  • Well passivated wafer with

different optics

[1] Juhl, M. K., Trupke, T., Abbott, M., & Mitchell, B. (2015). IEEE Journal of Photovoltaics, 5(6), 1840–1843. [2] Juhl, M. K., et at. (2015) 31st European Photovoltaic Solar Energy Conference Hamburg.

𝐵 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

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SLIDE 8

Application 1: Band-to-band Absorptance

  • Well passivated wafer with

different optics

  • Compared to:

1. Optical measurements 2. EQE measurements

[1] Juhl, M. K., Trupke, T., Abbott, M., & Mitchell, B. (2015). IEEE Journal of Photovoltaics, 5(6), 1840–1843. [2] Juhl, M. K., et.at. (2015) 31st European Photovoltaic Solar Energy Conference Hamburg.

𝐵 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

Comparison of Ar from our system to

  • ther measurement techniques

𝐵𝑠

1060,808 = 𝐵1060

𝐵808

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SLIDE 9

Application 1: Absorptance imaging!

A B A B

𝐵 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

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Application 1: Band-to-band Absorptance

  • Well passivated wafer with

different optics

  • Compared to:

1. Optical measurements 2. EQE measurements

[1] Juhl, M. K., Trupke, T., Abbott, M., & Mitchell, B. (2015). IEEE Journal of Photovoltaics, 5(6), 1840–1843. [2] Juhl, M. K., et.at. (2015) 31st European Photovoltaic Solar Energy Conference Hamburg.

𝐵 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

It works!!

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Application 2: External Quantum Efficiency

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Application 2: External Quantum Efficiency

𝐹𝑅𝐹𝐾𝑡𝑑 =

𝐽𝑡𝑑 𝑟𝑂𝑞ℎ

𝐹𝑅𝐹

𝑘𝑡𝑑 ∝ 𝑓

𝑊𝑝𝑑 𝑊𝑢

𝑂𝑞ℎ 𝐽𝑄𝑀 ∝ 𝑓

𝑗𝑊𝑝𝑑 𝑊𝑢

In low injection: 𝐹𝑅𝐹𝐾𝑡𝑑 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

𝐽𝑞𝑚 𝑂𝑞ℎ is proportional to the EQE

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SLIDE 13

DAQ Card + Computer Preamplifier Beam Splitter Sample High Powered LED Generation Reference PL Detection

The Experimental Setup

𝐹𝑅𝐹 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

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SLIDE 14

Standard SiNx Absorbing SiNx Lifetime Structures Cells

Standard EQE Measurement EQEPL Measurement The Experiment

𝐹𝑅𝐹 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

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SLIDE 15

The Result

Figure: Our results,

𝐹𝑅𝐹 ∝ 𝐽𝑞𝑚 𝑂𝑞ℎ

It works!

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Can determine:

  • The band-to-band absorptance, with imaging!
  • The external quantum efficiency

Conclusions for applications!

But EQEPL didn’t match with EQEjsc at ≈ 800 nm.

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Our results

[1] Mäckel, H., & Cuevas, A. (2001). In International Solar Energy Society Solar World Congress. Adelaide,

Similar results from literature [1]

Results

Impact of voltage independent carriers

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It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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SLIDE 20

It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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SLIDE 21

It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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SLIDE 22

It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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SLIDE 23

It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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SLIDE 24

It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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SLIDE 25

It wasn’t me![1] Voltage dependent carriers:

  • Depend on the junction

voltage Voltage independent carriers:

  • Do not depend on the junction

voltage

Voltage independent what?

[1] Glatthaar, M., et al. Journal of Applied Physics, 105(11). http://doi.org/10.1063/1.3132827

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SLIDE 26

Steady State Continuity Equation!

𝑒2𝑜[𝑦] 𝑒𝑦2 = 𝑜[𝑦] 𝑀2 − 𝛽𝑂𝛿𝑓−𝛽𝑦 𝐸 𝑜 = 𝐷𝑏𝑓

𝑦 𝑀 + 𝐷𝑐𝑓−𝑦 𝑀 + 𝐷𝑑𝑓−𝛽𝑦,

Inhomogeneous differential equation!:

𝑜 = 𝑜𝑤𝑒 + 𝑜𝑤𝑗𝑒, 𝑜𝑤𝑒 = 𝐷𝑏−𝑤𝑒𝑓

𝑦 𝑀 + 𝐷𝑐−𝑤𝑒𝑓 −𝑦 𝑀

𝑓

𝑟𝑊 𝑙𝑈,

𝑜𝑤𝑗𝑒 = 𝐷𝑏−𝑤𝑗𝑒𝑓

𝑦 𝑀 + 𝐷𝑐−𝑤𝑗𝑒𝑓 −𝑦 𝑀 + 𝐷𝑑−𝑤𝑗𝑒𝑓−𝛽𝑦 𝑂𝛿.

Voltage independent carriers

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SLIDE 27

Voltage independent carriers

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Cause’s error when caculating

  • Implied voltage from lifetime
  • Lifetime from voltage
  • Absorptance from average

excess carrier density

The impact

[1] Mäckel, H., & Cuevas, A. (2001). In International Solar Energy Society Solar World Congress. Adelaide [2] Abbott, M. D., Bardos, R. A., Trupke, et.al. (2007). Journal of Applied Physics, 102(4), 44502.

Comparison of Sun’s PL with Suns Voc [2] Comparison of EQEJsc to EQE from photoconductance [1]

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  • It’s complicated

𝑜 = 𝑜𝑤𝑒 + 𝑜𝑤𝑗𝑒,

  • So how do the 𝑜𝑤𝑗𝑒 behave?

The impact: When does it happen

Voltage independent carriers for a 180 um cell under an illumination wavelength

  • f 1000 nm.

𝜐𝑓𝑔𝑔,𝑛𝑗𝑜 = 100 × 𝑜𝑤𝑗𝑒 𝐻

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Lifetime for a less than 1% deviation between Voc and iVoc Lifetime for which 100 × 𝑜 > 𝑜𝑤𝑗𝑒

The impact: When does it happen

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Cause’s error when caculating

  • Implied voltage from lifetime
  • Lifetime from voltage
  • Absorptance measurements

The impact

[1] Mäckel, H., & Cuevas, A. (2001). In International Solar Energy Society Solar World Congress. Adelaide [2] Abbott, M. D., Bardos, R. A., Trupke, et.al. (2007). Journal of Applied Physics, 102(4), 44502.

Comparison of Sun’s PL with Suns Voc [2] Comparison of EQEJsc to EQE from photoconductance [1]

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  • PL  well passivated samples  Band-to-band absorptance
  • PL  no voltage independent carriers EQE
  • The carrier density can be described in terms of a voltage

dependent and independent term.

  • Conversion from Voltage to lifetime does not always work.

Thank You! Conclusions