Download presentation

Presentation is loading. Please wait.

Published byAbigayle Hartgrove Modified over 3 years ago

1
Rare-earth doped fluorides for silicon solar cell efficiency enhancement Diana Serrano Garcia A.Braud, P.Camy, J-L.Doualan, A.Benayad, V.Menard, R.Moncorge CIMAP, University of Caen, France

2
Summary Limitations of solar energy conversion Downconversion: Quantum cutting Experimental results and models Conclusion Quantum cutting with Rare-earth doped fluorides

3
Photovoltaics (PV) - Conversion of solar energy into electricity Silicon as the most famous semiconductor for solar cell development* Si doped n Si doped p +²+² - - Electron-hole pairs creation *R. Singh; Journal of Nanophotonics, 3 (2009)

4
I) Silicon limitations for solar spectrum conversion Short wavelenghts BC BV Si Gap =1,12eV E - Energy loss due to carrier thermalization - Absorption of photons h >1,12 eV Energy lost

5
CB VB 1,12eV E - Silicon transparent for h <1,12 eV. Low efficiency for Silicon solar cells (a-Si 9%,c-Si 25%*) Silicon limitations for solar spectrum conversion Long wavelenghts *M.Green, Progress in Photovoltaics : Research and Applications 17, 320 (2009)

6
Stacking of semiconductors with different bandgaps SC 2SC 1SC 3 Decreasing bandgap Semicond. 1 Semicond. 2 Semicond. 3 Solution I: multi junction solar cells The larger bandgap at the surface of the device BUT: expensive and difficult to produce Aerospace Applications High efficiency (World record 40% * ) *M.Green, Progress in Photovoltaics : Research and Applications 17, 320 (2009)

7
Si 2 e - Quantum cutting Solution II: Frequency Conversion hνhν hνhν hνhν Efficiency enhancement Quantum Cutting Low cost production *T. Trupke, M. Green; Journal of applied physics 92, 3 (2002) 1668 Ideal converter 36,6%* c-Si Solar Cell Si Quantum cutting layer

8
Downconversion: Quantum cutting by energy transfer Donor Acceptor E D0D0 A0A0 D1D1 D2D2 A1A1 A0A0 A1A1 D 2 D 1 and A 0 A 1 D 1 D 0 and A 0 A 1 Donor excitation D 0 D 2 Acceptor relaxation A 1 A 0 2 photons emission Energy transfer 1 Energy transfer 2 hv/2 hv Getting 2 photons from 1 photon? 1 2 From 1 photon we get 2 photons

9
Quantum cutting with rare-earth doped fluorides: ►Why Yb? E~10000 cm -1 ~1,2eV ~ Si Gap Yb 3+ Pr 3+ Yb 3+ Donor Acceptor Pr 3+ /Yb 3+ system E( 3 P 0 – 1 G 4 )~E( 2 F 5/2 – 2 F 7/2 ) E( 1 G 4 – 3 H 4 )~E( 2 F 5/2 – 2 F 7/2 ) Acceptor E ►Why Pr ? Resonant Energy Transfer 1 2

10
Host matrix: Fluorides - Low phonon energy High fluorescence quantum yield - Large transparency range Differences: RE 3+ doping Short distance between ions Very efficient energy transfer KY 3 F 10 Uniform distribution of dopants CaF 2 Formation of complexes (clusters)

11
CaF 2 :Pr/Yb First energy transfer Pr Yb Intensity ratio as a function of Yb concentration Pr excitation Increase of first transfer Pr ( 3 P 0 ) Yb ( 2 F 5/2 ) with Yb concentration Pr 3+ Donor Yb 3+ Acceptor Transfer Ytterbium emission under Pr ( 3 P 0 ) excitation Energy transfer from Pr to Yb (%Pr constant at 0.5%) Experimental Results

12
3 P 0 fluorescence decay in CaF 2 and KY 3 F 10 Decrease of ( 3 P 0 ) with Yb concentration for both hosts Experimental Results Energy transfer rate : Energy transfer efficiency :

13
Experimental Results 97% eficiency with 4% Yb in CaF 2 96% eficiency with 20% Yb in KY 3 F 10 Transfer in CaF 2 more efficient than transfer in KY 3 F 10 Efficiency (%)

14
Modeling I: Classical model 3 energy transfer - Possible interaction between all Pr and Yb ions - Uniform ion distribution

15
6 possible states 3H43H4 2 F 5/2 3P03P0 1G41G4 2 F 7/2 Pr 3+ Yb 3+ Limited interaction within the pair P 1 +P 2 +P 3 +P 4 +P 5 +P 6 =1 Each state has a probability P i Modeling II: Pair model

16
Conclusion Possible QC with CaF 2 :Pr/Yb and KY 3 F 10 : Pr/Yb Transfer in CaF 2 more efficient! Implementation in Si solar cells Very efficient Pr Yb first transfer (97%) Conclusions New models (Three or more ions model??)

17
THANK YOU for your attention!!

Similar presentations

OK

Light management in thin-film solar cells Albert Polman Center for Nanophotonics FOM-Institute AMOLF Amsterdam, The Netherlands.

Light management in thin-film solar cells Albert Polman Center for Nanophotonics FOM-Institute AMOLF Amsterdam, The Netherlands.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on personality development skills Ppt on zener diode voltage Ppt on fibre reinforced concrete Ppt on tropical evergreen forest Ppt on complex numbers class 11th sample Ppt on nuclear family and joint family history Ppt on event driven programming disadvantages Download ppt on 3d printing technology Ppt on different types of forests names Ppt on security attacks in information security