1. XUV DIAMOND DETECTORS Antonio De Sio Dep. of Astronomy and Space Science University of Firenze, Italy

2. Antonio De Sio WUTA 20082 XUVLab Diamond activities Research design and development of diamond based photodetectors Research design and development of diamond based photodetectors Study and Characterization of single crystal and polycrystalline diamond detectors in VUV spectral range Study and Characterization of single crystal and polycrystalline diamond detectors in VUV spectral range Study and characterization of polycrystalline and single crystal diamond detectors in the X-ray Study and characterization of polycrystalline and single crystal diamond detectors in the X-ray

3. Antonio De Sio WUTA 20083 Collaborations University of Firenze, Italy University of Firenze, Italy A. De Sio, E. Pace, A. Giannini Laboratori Nazionali di Frascati, INFN, Italy Laboratori Nazionali di Frascati, INFN, Italy A. Marcelli, C. Castellano, D. Hampai University of Roma “Tor Vergata” University of Roma “Tor Vergata” M. Marinelli, G. Verona-Rinati Diamond Synchrotron Light Source Diamond Synchrotron Light Source G. Cinque, G. Cibin, N. Tartoni Italian CNR - GILDA BEAMLINE – ESRF Italian CNR - GILDA BEAMLINE – ESRF F. D’Acapito, S. Mobilio Fraunhofer Institute – Freiburg Fraunhofer Institute – Freiburg C. Wild, E. Woerner

4. Antonio De Sio WUTA 20084 Ideal XUV detector Very low noise Radiation hardness Visible blindness Chemical inertness High sensitivity REQUESTS Large area

5. Antonio De Sio WUTA 20085 Radiation Hardness High XUV sensitivity Low Power Absorption Very Low Noise Chemical inertness Solar Blindness Energy Gap 5.5 eV Strong Chemical Bond Mechanical Robust Few Thermal Carrier Low Dark Currents (< pA) 225nm Cutoff Wavelength Electric Properties High electric charge mobility Low dielectric constant Fast response time Low Capacitance No Cooling High Signal Gain Why diamond

6. Antonio De Sio WUTA 20086 Summary  Diamond detectors  Dark Current  Visible blindness  Sensitivity spectra  Linearity of the response with flux  Response time  Photoconductive Gain

7. Antonio De Sio WUTA 20087 DETECTORS

8. 8 Diamond detectors hν Coplanar geometry hν Transverse geometry MSM structure

9. Antonio De Sio WUTA 20089 External quantum efficiency

10. Antonio De Sio WUTA 200810 Diamond Devices: Single pixel detectors Diamond layer Interdigitated electrodes

11. Antonio De Sio WUTA 200811Electrodes Diamond layer Diamond Devices: Single pixel detectors

12. Antonio De Sio WUTA 200812 Pixel array detectors Lift-off photolitographic technique Lift-off photolitographic technique Al contacts (blocking) Al contacts (blocking) 20  m interelectrode spacing 20  m interelectrode spacing 70  m pitch 70  m pitch

13. Antonio De Sio WUTA 200813 DARK CURRENT

14. Antonio De Sio WUTA 200814 Photodetectors dark current

15. Antonio De Sio WUTA 200815 VISIBLE BLINDNESS

16. Antonio De Sio WUTA 200816 Visible blindness 2004006008001000 1E-8 1E-7 1E-6 1E-5 1E-4 1E-3 0,01 0,1 1 10 100 E = 2.8 V/  m UV / VIS > 10 8 External quantum efficiency Wavelength (nm) E. Pace et al., Diam. Rel. Mater. (2000)

17. Antonio De Sio WUTA 200817 UV Pulsed mode measurements Responsivity lower than our detection limit at >1300 nm Responsivity lower than our detection limit at >1300 nm Substrate contribution at >225 nm (Nitrogen impurities in the Ib substrate) Substrate contribution at >225 nm (Nitrogen impurities in the Ib substrate) Stable and highly reproducible detector response Stable and highly reproducible detector response Undesirable memory effects as well as pumping ARE NOT OBSERVED Undesirable memory effects as well as pumping ARE NOT OBSERVED

18. Antonio De Sio WUTA 200818 SENSITIVITY SPECTRA

19. Antonio De Sio WUTA 200819 EUV detection capabilities  Emission spectrum of a DC discharge He and He-Ne lamp  HeII 25.6 nm and 30.4 nm HeI as well 58.4 nm emission lines clearly detected  Good detection capability of the device even in this extreme UV spectral region  High signal to noise ratio, in spite of the pA range of the output photocurrent He Sample: SCD 8 He-Ne Sample: SCD 31

20. Antonio De Sio WUTA 200820 EUV electro-optical performance

21. Antonio De Sio WUTA 200821 DUV electro-optical performance

22. Antonio De Sio WUTA 200822 LINEARITY

23. Antonio De Sio WUTA 200823 UV Pulsed mode measurements 215 nm illumination 215 nm illumination Linearity test by systematically varying the optical diffuser to diamond detector distance Linearity test by systematically varying the optical diffuser to diamond detector distance Detector response as a function of the calculated incident energy Detector response as a function of the calculated incident energy Good linear behaviour Good linear behaviour

24. Antonio De Sio WUTA 200824Linearity λEQEmEQEcDiff. 2000.01290.01354.5% 2100.008630.008136% Diamond sc-HPHT Coplanar contacts Gold Contacts

25. Antonio De Sio WUTA 200825 RESPONSE TIME

26. Antonio De Sio WUTA 200826 Time response and PPC

27. Antonio De Sio WUTA 200827 Time response and PPC

28. Antonio De Sio WUTA 200828 Time response and PPC

29. Antonio De Sio WUTA 200829 Time response and PPC @160 nm sc-HPHT 1 V/μm

30. Antonio De Sio WUTA 200830 PHOTOCONDUCTIVE GAIN

31. Antonio De Sio WUTA 200831 Photoconductive Gain Diamond sc-CVD Coplanar contacts Gold contacts

32. Antonio De Sio WUTA 200832 Photoconductive Gain Single pixel device Material from LIMHP-CNRS Material from LIMHP-CNRS Device built and tested in Firenze Device built and tested in Firenze Single crystal CVD diamond Single crystal CVD diamond Free standing Free standing Mechanically polished Mechanically polished Au electric contacts on both surfaces Au electric contacts on both surfaces De Sio et al. Appl. Phys. Lett. 2005

33. Antonio De Sio WUTA 200833 DUV electro-optical performance

34. Antonio De Sio WUTA 200834 Good spatial resolution (negligible cross-talk) and fast response times Good spatial resolution (negligible cross-talk) and fast response times Good sample homogeneity Good sample homogeneity Very good stability and reproducibility Very good stability and reproducibility  Pixel array characterization with 5 ns laser pulses at 215 nm (preliminary)  Three adjacent pixels of the array  Focusing of the laser beam on the pixel marked with * Pixel array: cross talk

35. Antonio De Sio WUTA 200835 Conclusion Single crystal and polycrystalline diamond based UV single pixel and pixels array devices can be fabricated Single crystal and polycrystalline diamond based UV single pixel and pixels array devices can be fabricated  Low dark current values  High XUV sensitivity was observed  Good response times  No persistent photoconductivity  No pumping effects  Negligible cross-talk in pixel arrays

36. Antonio De Sio WUTA 200836

37. Antonio De Sio WUTA 200837 X-Ray

38. Antonio De Sio WUTA 200838 X-ray detection Cu X-ray source 30kV Fast response time (less than 0.2 s) Good reproducibility No persistent photocurrent No memory effects No Pumping effect Good stability X-Ray detection

39. Antonio De Sio WUTA 200839 Response stability 50 mins of simultaneous measurements with IC and diamond detector at 10 KeV. Differences are below 0.4% during the whole measurement.

40. Antonio De Sio WUTA 200840 Linearity with X ray intensity HPHT - SRS Poly N doped - Stanford Loosen correlation between IC and diamond response

41. Antonio De Sio WUTA 200841 Linearity with X ray intensity

42. Antonio De Sio WUTA 200842 K edge Fe Absorption HPHT 1b Diamond Polycrystalline Diamond N doped

43. Antonio De Sio WUTA 200843 EXAFS Signal HPHT 1b Diamond Polycrystalline Diamond N doped

44. Antonio De Sio WUTA 200844 Fourier Analysis Vs Theoretical HPHT 1b Diamond Polycrystalline Diamond N doped

45. Antonio De Sio WUTA 200845 EXAFS Results Ion Chamber N1 : 8.0 ± 0.0 SIG1^2 : 4.53E-03 R1 : 2.48 ± 0.01 N2 : 6.0 ± 0.0 SIG2^2 : 6.6E-03 R2 : 2.89 ± 0.01 Residual = 1.19E-02 Diamond N1 : 8.0 ± 0.0 SIG1^2 : 4.3E-03 R1 : 2.48336 ± 0.01 N2 : 6.0 ± 0.0 SIG2^2 : 6.5E-03 R2 : 2.89894 ± 0.01 Residual = 1.12E-02 Ion Chamber N1 : 8.0 ± 0.0 SIG1^2 : 5.19E-03 R1 : 2.49 ± 0.01 N2 : 6.0 ± 0.0 SIG2^2 : 1.11E-2 R2 : 2.895 ± 0.01 Residual = 1.20E-02 Diamond N1 : 8.0 ± 0.0 SIG1^2 : 4.53E-03 R1 : 2.48 ± 0.01 N2 : 6.0 ± 0.0 SIG2^2 : 8.88E-03 R2 : 2.905 ± 0.01 Residual = 1.25E-02 HPHT - 1bPoly N doped Good agreement between IC and Diamond detector and with the theoretical data