Investigation of the current-voltage characteristics, the electric field distribution and the charge collection efficiency in x-ray sensors based on chromium compensated gallium arsenide

A. Tyazhev; V. Novikov; O. Tolbanov; A. Zarubin; M. Fiederle; E. Hamann

doi:10.1117/12.2061302

5 September 2014 Investigation of the current-voltage characteristics, the electric field distribution and the charge collection efficiency in x-ray sensors based on chromium compensated gallium arsenide

A. Tyazhev, V. Novikov, O. Tolbanov, A. Zarubin, M. Fiederle, E. Hamann

Author Affiliations +

Proceedings Volume 9213, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVI; 92130G (2014) https://doi.org/10.1117/12.2061302
Event: SPIE Optical Engineering + Applications, 2014, San Diego, California, United States

Abstract

In this work we present the results of experimental study of the current-voltage characteristics, the electric field distribution and the charge collection efficiency in X-ray sensors based on high resistivity, chromium compensated gallium arsenide (HR GaAs). The experimental samples were 0.1-0.25 cm² pad sensors with the sensitive layer thickness in the range of 250-1000 μm. It has been shown that the current-voltage characteristics in the range 0.02 – 1 V are determined by the high-resistance sensor bulk. A physical model of the nonequilibrium charge carrier transport has been suggested to estimate the Schottky barrier height in the contact of “metal-semiconductor” and the sensor material resistivity. It has been established that the sensor resistivity reaches 1.5 GOhm⋅cm at room temperature, with the Schottky barrier height constituting 0.80 – 0.82 eV. The electric field distribution was investigated using the Pockels effect at a wavelength of 920 nm. It has been found experimentally that in HR GaAs sensors the electric field distribution is much more homogeneous compared to the sensors based on SI GaAs: EL2. It has been shown that the temporal fluctuations of the electric field are absent in HR GaAs sensors. Analysis of the charge collection efficiency as a function of bias has demonstrated, that in the HR GaAs material the values of the mobility-lifetime product of the nonequilibrium charge carriers are in the order of 10^-4 cm2/V and 3⋅10^-7 cm2/V for electrons and holes, respectively.

Citation Download Citation

A. Tyazhev, V. Novikov, O. Tolbanov, A. Zarubin, M. Fiederle, and E. Hamann "Investigation of the current-voltage characteristics, the electric field distribution and the charge collection efficiency in x-ray sensors based on chromium compensated gallium arsenide", Proc. SPIE 9213, Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVI, 92130G (5 September 2014); https://doi.org/10.1117/12.2061302

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available