Speaker
Pavel Murat
(Fermi National Accelerator Laboratory)
Description
We measured response to 5.5 MeV alpha particles of a 20 um thick integrated
scintillating detector based on InAs quantum dots (QDs) embedded into GaAs matrix.
The operational principle of the tested detector is as follows: photons emitted
by InAs QDs have energy lower than the GaAs bandgap, which makes the GaAs bulk
transparent to the QD emission. The QD emission is detected by a 1 um thick
InGaAs photodiode, integrated with the scintillator. The detector has been
successfully operated in a photo-voltaic, or zero-bias mode, without an external
bias voltage applied to the photodiode.
Compared to one of the best inorganic scintillators, LYSO, a QD/semiconductor-based
scintillator has about 5x higher light yield (~240,000 photons/MeV), and ~ 40x faster
decay time (1 ns). That should result in the timing resolution of 1-10 ps,
energy resolution close to 1% at ~1 MeV at room temperature, and counting rates > 100 MHz per readout channel.
We present measurements of the energy response, attenuation length, estimates
of the expected timing resolution, and discuss radiation hardness.
Produced in thin films, QD-based scintillating detectors could provide an interesting
solution for low mass solid-state tracking of charged particles in high-rate
experiments which require an excellent timing resolution and coordinate resolution
of the order of 100 um. Their ability to operate without an external bias makes such detectors very distinct from widely used in HEP Si detectors.
Primary authors
Pavel Murat
(Fermi National Accelerator Laboratory)
Prof.
Serge Oktyabrsky
(SUNY Polytechnic Institute, Albany)
Co-authors
Mr
Allan Minns
(SUNY Polytechnic Institute, Albany)
Mr
Christian Gingu
(Fermilab)
Ms
Katherine Dropiewsky
(SUNY Polytechnic Institute)
Ms
Maya Chattoraj
(University of Illinois, Urbana Champain)
Dr
Michael Yakimov
(SUNY Polytechnic Institute, Albany)
Mr
Sergey Los
(Fermilab)
Dr
Vadim Tokranov
(SUNY Polytechnic Institute, Albany)
