Mechanism of low schottky barrier formation for chromium/CdZnTe contact

Low Schottky barrier electrode has great significance on CdZnTe semiconductor nuclear radiation detectors. In this work, synchrotron radiation photoemission spectroscopy (SRPES) has been used to study the interface electronic structure of chromium (Cr) and CdZnTe with Cr coverage thicknesses ranging from 6 to 45.7 Å. Interface reaction and diffusion happen during the Cr deposition. A new interface structure CdZnTe-Cr-Te hence forms, which causes a positive dipole layer at the interface. Schottky barrier height (SBH) is reduced by 0.34 eV due to the dipole layer. Cr/CdZnTe interface structure can effectively change the SBH. Therefore, Cr can be a favorable low Schottky barrier electrode material for CdZnTe detector.