Vacuum UltraViolet (VUV) Spectroscopy of TPB films

1. VacuumUltraViolet (VUV) Spectroscopyof TPB films Temperature Effect on TPB Emission Lineshape Roberto Francini DepartmentofPhysics Università di Roma Tor Vergata Contacts: francini@roma2.infn.it +39 06 7259 4505 SLIDE 1 TPB Workshop 10/19/2012

2. Investigated TPB samplesweregrown at the Gran Sasso National Laboratory LNGS, INFN L’Aquila, Italy Samples obtained by dip-coating of glass substrates in polystyrene containing TPB Samples obtained by evaporation of TPB on different substrates SLIDE 2 TPB Workshop 10/19/2012

3. Jablonskydiagram SLIDE 3 TPB Workshop 10/19/2012

4. Configurationalcoordinates diagram PhotoLuminescence (PL) Spectra AbsorptionSpectra PhotoExcitation (PE) Spectra SLIDE 4 TPB Workshop 10/19/2012

5. VacuumMonochromatorMcPhersonmodel 234/302 Focallength 0.2 m equippedwith a 30 WattsDeuteriumlampmodel 632 with MgF2 window, Spectralrange 115 – 380 nm. Closed-cycleHeliumCryostat Temperature range 12 – 300 K SLIDE 5 TPB Workshop 10/19/2012

6. Measured VUV IntensitydistributionofDeuteriumlamp 128 nm SLIDE 6 TPB Workshop 10/19/2012

7. TPB in polystyrene on glass EmissionSpectra Excited at 128 nm AbsorptionSpectra SLIDE 7 TPB Workshop 10/19/2012

8. TPB in polystyrene TPB in PMMA J. Huang et al., J. Lumin. 81 (4), 285 (1999) SLIDE 8 TPB Workshop 10/19/2012

9. TPB evaporated on glass Spettri di Emissione Eccitati a 128 nm EmissionSpectraExcited at 128 nm SLIDE 9 TPB Workshop 10/19/2012

10. TPB evaporated on VIKUITI EmissionSpectraExcited at 128 nm SLIDE 10 TPB Workshop 10/19/2012

11. mm (0,0) T = 12 K (0,4) Frank-CondonIntegrals (0,5) S = 2 Huang-RhysFactor ΔQis the coordinate displacement between the ground state and the excited state - Vibrational mode energy = 0.18 eV = 1450 cm -1 - Stretching mode vibrationoftrans-butadiene SLIDE 11 TPB Workshop 10/19/2012

12. TPB in polystyrene on glass EmissionSpectraExcited at 128 nm EmissionSpectraof TPB on VIKUITI and in polystyrene Excited at 128 nm Temperatura 87 K (LAr) SLIDE 12 TPB Workshop 10/19/2012

13. Photoluminescence (PL) and Photoexcitation (PE) in the UV-VIS range TPB in polystyrene on glass – T = 300 K TPB evaporated on VM2000 – 600 μg/cm2 – T = 300 K SLIDE 13 TPB Workshop 10/19/2012

14. T = 300 K EmissionSpectra (excited at 128 nm) of TPB evaporated on VIKUITI, TPB in polystyrene on glass and of a VIKUITI blank, comparedwith the emissionspectrumof a SodiumSalicylate film on glass. SLIDE 14 TPB Workshop 10/19/2012