Evaluation of NH4F/H2O2 effectiveness as a surface passivation agent for Cd1-xZnxTe crystals

Various passivating agents that reduced the surface leakage current of CZT crystals have been previously reported. In one of the studies, NH4F/H2O2 was identified as a promising passivation agent for CZT. We now present a study that includes the effect of NH4F/H2O2 treatment on the surface properties and detector performance. An elemental depth profile was obtained via Auger Electron Spectroscopy. Furthermore, X-ray Photoelectron Spectroscopy acquired at different processing times to identify the chemical states of the elemental species that composed the dielectric layer. It was found that the NH4F/H2O2 surface passivation significantly improved the sensitivity and energy resolution of CZT detectors. Furthermore, the NH4F/N2O2 treatment did not attack the Au electrodes, which eliminated the need to protect the contacts in the detector fabrication process.