Sub-microsecond x-ray imaging using hole-collecting Schottky type CdTe with charge-integrating pixel array detectors

CdTe is increasingly being used as the x-ray sensing material in imaging pixel array detectors for x-rays, generally above 20 keV, where silicon sensors become unacceptably transparent. Unfortunately CdTe suffers from polarization, which can alter the response of the material over time and with accumulated dose. Most prior studies used long integration times or CdTe that was not of the hole-collecting Schottky type. We investigated the temporal response of hole-collecting Schottky type CdTe sensors on timescales ranging from tens of nanoseconds to several seconds. We found that the material shows signal persistence on the timescale of hundreds of milliseconds attributed to the detrapping of a shallow trap, and additional persistence on sub-microsecond timescales after polarization. The results show that this type of CdTe can be used for time resolved studies down to approximately 100 ns. However quantitative interpretation of the signal requires careful attention to bias voltages, polarization and exposure history.

[1]  Klaus Giewekemeyer,et al.  High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector , 2014, Journal of synchrotron radiation.

[2]  O. Tolbanov,et al.  The LAMBDA photon-counting pixel detector and high-Z sensor development , 2014 .

[3]  Hugh T. Philipp,et al.  A Medium-Format, Mixed-Mode Pixel Array Detector for Kilohertz X-ray Imaging , 2013 .

[4]  Kazuhiko Suzuki,et al.  Time-of-Flight Measurements on Schottky CdTe Detectors , 2012, IEEE Transactions on Nuclear Science.

[5]  Hugh T. Philipp,et al.  Characterization of CdTe sensors with Schottky contacts coupled to charge-integrating pixel array detectors for X-ray science , 2016, 1609.03513.

[6]  Raffaella Geometrante,et al.  Construction of CHESS compact undulator magnets at Kyma , 2015, Europe Optics + Optoelectronics.

[7]  Ezio Caroli,et al.  Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications , 2009, Sensors.

[8]  E. Fontes,et al.  Compact Undulator for the Cornell High Energy Synchrotron Source: Design and Beam Test Results , 2013 .

[9]  K. Perez Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2014 .

[10]  R. Klanner,et al.  Measurements of charge carrier mobilities and drift velocity saturation in bulk silicon of a , 2011 .

[11]  K. Vecchio,et al.  Time-resolved x-ray diffraction techniques for bulk polycrystalline materials under dynamic loading. , 2014, The Review of scientific instruments.

[12]  M. Tate,et al.  Calibration and post-processing for photon-integrating pixel array detectors , 2013 .

[13]  Klaus-Werner Benz,et al.  Modified compensation model of CdTe , 1998 .

[14]  M. Tate,et al.  High-speed X-ray imaging pixel array detector for synchrotron bunch isolation , 2016, Journal of synchrotron radiation.

[15]  E. Belas,et al.  Determination of Electric-Field Profile in CdTe and CdZnTe Detectors Using Transient-Current Technique , 2012, IEEE Transactions on Nuclear Science.

[16]  Kazuhiko Suzuki,et al.  Carrier transport properties of HPB CdZnTe and THM CdTe:Cl , 2001, 2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310).

[17]  Paul J. Sellin,et al.  Recent advances in compound semiconductor radiation detectors , 2003 .

[18]  M. Tate,et al.  An Accumulating Pixel Array Detector for Single-Bunch Synchrotron Experiments , 2009, IEEE Transactions on Nuclear Science.

[19]  Philipp Lodomez,et al.  Characterization of charge collection in CdTe and CZT using the transient current technique , 2006 .

[20]  R. Klanner,et al.  Measurements of charge carrier mobilities and drift velocity saturation in bulk silicon of and crystal orientation at high electric fields , 2010, 1007.4432.

[21]  S. Gruner,et al.  X-ray analog pixel array detector for single synchrotron bunch time-resolved imaging. , 2010, Journal of synchrotron radiation.

[22]  Veit Elser,et al.  Real-Space x-ray tomographic reconstruction of randomly oriented objects with sparse data frames. , 2013, Optics express.

[23]  W. Vernon,et al.  First results from the 128x128 pixel mixed-mode Si x-ray detector chip , 2007, SPIE Optical Engineering + Applications.

[24]  Sandor L. Barna,et al.  Tests of a prototype pixel array detector for microsecond time-resolved X-ray diffraction , 1999 .