260 likes | 434 Views
Ingredients of a good scientific talk. Justin Hodgkiss SCPS postgraduate workshop 15 January 2013. Goal. To get the audience to appreciate your science story. What’s the story?. Be very clear in your head before making slides. Distil Distil Distil. 1 sentence?. What’s the story?.
E N D
Ingredients of a good scientific talk Justin Hodgkiss SCPS postgraduate workshop 15 January 2013
Goal To get the audience to appreciate your science story
What’s the story? Be very clear in your head before making slides Distil Distil Distil 1 sentence?
What’s the story? Be very clear in your head before making slides • Where are you going?
Choose structure to fit the story Thinkcreatively 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
Value the first minute One chance to hook the audience – don’t blow it! Must be stimulating Get to the point
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
Light absorption triggers a cascade if photophysical processes in OPVs
Exciton bottleneck – model must be wrong! Adv. Funct. Mat., 15(10): 1617-1622. 100nm Adv. Mat. 20 (18): 3516-3520 Optimized domains ~10-20 nm Physical Review Letters 108(5): 056603. Exciton diffusion coefficients (10-3 cm2 s-1 for P3HT) only ~0.1 nm in 100 fs Free charge carrier generation within 40 fsafter photoexcitation
Charge separation prior to exciton formation? Delocalized excitation ‘Hot CT’ Thermalization (sub ps) Separated charges Localized exciton hn Fluorescence Ground state
Ultrafast formation of free charges 1. Charge delocalization dynamics via time resolved absorption cross-section 2. Role of the exciton via ultrafast photoluminescence
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.
Ultrafast formation of free charges 1. Charge delocalization dynamics via time resolved absorption cross-section 2. Role of the exciton via ultrafast photoluminescence
Each slide makes a point • Clean, minimal, balanced • Clear, relevant graphics • Large font
Growth in charge absorption tracks PL decay These charges are formed via bound emissive excitons
Clarity is key • Use every means to make it EASY TO FOLLOW • Colour coding
Light absorption triggers a cascade if photophysical processes in OPVs
Exciton bottleneck – model must be wrong! Adv. Funct. Mat., 15(10): 1617-1622. 100nm Adv. Mat. 20 (18): 3516-3520 Optimized domains ~10-20 nm Physical Review Letters 108(5): 056603. Exciton diffusion coefficients (10-3 cm2 s-1 for P3HT) only ~0.1 nm in 100 fs Free charge carrier generation within 40 fsafter photoexcitation
Clarity is key • Use every means to make it EASY TO FOLLOW • Colour coding • Repeated imagery
Evidence for charge separation prior to exciton formation ‘Hot CT’ Delocalized excitation Thermalization (sub ps) Separated charges Localized exciton hn Fluorescence Ground state
Clarity is key • Use every means to make it EASY TO FOLLOW • Colour coding • Repeated imagery • Eliminate jargon
Practice, practice, practice • Out loud (record) • KEEP TO TIME • Remember: • Key point of each slide • Transitions • Crucial concepts to emphasize…. Slow down
Preparations on the day • Multiple copies (USB, dropbox, email…), + printout • .pdf version • Check display, animation, video’s, lighting, Mac?? • Pointer • Timer • Where to stand?
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
Reflect on the best and worst talks you’ve seen … best and worst talks you’ve given?