1. Ingredients of a good scientific talk Justin Hodgkiss SCPS postgraduate workshop 15 January 2013

2. Goal To get the audience to appreciate your science story

3. What’s the story? Be very clear in your head before making slides Distil 1 sentence?

4. What’s the story? Be very clear in your head before making slides Where are you going?

5. Choose structure to fit the story Think creatively What does audience need to know to appreciate story? Don’t be constrained by: - Structure used by everyone else - Your previous talks - desire to include everything you know

6. Value the first minute One chance to hook the audience – don’t blow it! Must be stimulating Get to the point

7. Outline Introduction to organic solar cells - Excitons - Charge generation Experimental methods - Optical Kerr gate - Transient absorption spectroscopy Results - Exciton dynamics - Measurement of cross-sections Conclusions Acknowledgements

8. Light absorption triggers a cascade if photophysical processes in OPVs

9. Exciton diffusion coefficients (10 -3 cm 2 s -1 for P3HT)  only ~0.1 nm in 100 fs Adv. Mat. 20 (18): 3516-3520 Optimized domains ~10-20 nm 100nm Adv. Funct. Mat., 15(10): 1617-1622. Exciton bottleneck – model must be wrong! Free charge carrier generation within 40 fs after photoexcitation Physical Review Letters 108(5): 056603.

10. Charge separation prior to exciton formation? Delocalized excitation Ground state Localized exciton Separated charges Thermalization (sub ps) Fluorescence h ‘Hot CT’

11. Ultrafast formation of free charges 1. Charge delocalization dynamics via time resolved absorption cross-section 2. Role of the exciton via ultrafast photoluminescence

12. Ultrafast formation of free charges 1. Charge delocalization dynamics via time resolved absorption cross-section Friend, R. H. et. al. Science, 2012, 335, 1340-1344.

13. ……….. ………

14. Ultrafast formation of free charges 1. Charge delocalization dynamics via time resolved absorption cross-section 2. Role of the exciton via ultrafast photoluminescence

15. Each slide makes a point Clean, minimal, balanced Clear, relevant graphics Large font

16. Growth in charge absorption tracks PL decay These charges are formed via bound emissive excitons

17. Clarity is key Use every means to make it EASY TO FOLLOW – Colour coding

18. Light absorption triggers a cascade if photophysical processes in OPVs

19. Exciton diffusion coefficients (10 -3 cm 2 s -1 for P3HT)  only ~0.1 nm in 100 fs Adv. Mat. 20 (18): 3516-3520 Optimized domains ~10-20 nm 100nm Adv. Funct. Mat., 15(10): 1617-1622. Exciton bottleneck – model must be wrong! Free charge carrier generation within 40 fs after photoexcitation Physical Review Letters 108(5): 056603.

20. Clarity is key Use every means to make it EASY TO FOLLOW – Colour coding – Repeated imagery

21. Evidence for charge separation prior to exciton formation Delocalized excitation Ground state Localized exciton Separated charges Thermalization (sub ps) Fluorescence h ‘Hot CT’

22. Clarity is key Use every means to make it EASY TO FOLLOW – Colour coding – Repeated imagery – Eliminate jargon

23. Practice, practice, practice Out loud (record) KEEP TO TIME Remember: – Key point of each slide – Transitions – Crucial concepts to emphasize…. Slow down

24. Preparations on the day Multiple copies (USB, dropbox, email…), + printout.pdf version Check display, animation, video’s, lighting, Mac?? Pointer Timer Where to stand?

25. Relax and enjoy the moment Easy if you’re well prepared! Time flies Don’t panic if you forget something……. Just slow down and keep it simple

26. Reflect on the best and worst talks you’ve seen … best and worst talks you’ve given?