Abstract
Over the past decades (CdZn)Te crystals have been proven to be high-quality detectors of X-and gamma-radiation. However, surface quality, in particular, surface resistivity and long-time stability strongly affect the device performance.
Surface passivation is a common technique used for the surface improvement, but yet known methods are particularly ineffective. Recent studies showed promising results with a hydrogen peroxide and sulfide-based treatment of the surface, nevertheless obtained samples still suffer from the surface aging process and consequent degradation of the detecting properties.
In our work, we introduce two-stage treatment of (CdZn)Te samples followed by the polymerisation of unsaturated hydrocarbons, which can protect the surface from the impact of the medium and thus improve its long-time stability. We propose a method of passivation of as-etched crystals.
It involves two consecutive processes: the activation of the surface in the sulfide solution and treatment in the alkene medium. After the final preparation step the surface resistance was enhanced almost by 50 % in comparison with the initial etched sample, and it remained stable over two weeks.
Our results can be used in commercial production of (CdZn)Te detectors as an up-and-coming method of preserving their electrical properties over time.