Effects of Chemical Treatments on CdZnTe X-Ray and Gamma-Ray Detectors

Analysis of Te and TeO<sub>2</sub> on CdZnTe Nuclear Detectors Treated with Hydrogen Bromide and Ammonium-Based Solutions

“…Three wafers (samples 1, 2 and 3) were selected from a set that were cut with a pre-set dimensions of 6.4 mm × 6.4 mm × 2.8 mm, similar to those used in our other investigations [11] [14] [15]. The fabrication steps for each sample are summarized in Table 1.…”

“…The third stage is surface passivation using appropriate chemicals. In addition to reducing fabrication-induced defects, surface passivation also limits aging defects [11] [12] [13] [14].…”

“…In previous investigations, we compared the passivation of CdZnTe detectors using ammonium fluoride (NH 4 F) in hydrogen peroxide and potassium hydroxide (KOH) in hydrogen peroxide solutions [11]. It was reported that the NH 4 F-based solution is more effective than that of KOH at converting Te species on the CdZnTe wafer surfaces into a more stable TeO 2 layer [11].…”

“…It was reported that the NH 4 F-based solution is more effective than that of KOH at converting Te species on the CdZnTe wafer surfaces into a more stable TeO 2 layer [11]. It was observed that freshly passivated CdZnTe wafer in the NH 4 F-based chemical contributed less to the leakage current compared to that passivated with the KOHbased solution [11].…”

“…It was reported that the NH 4 F-based solution is more effective than that of KOH at converting Te species on the CdZnTe wafer surfaces into a more stable TeO 2 layer [11]. It was observed that freshly passivated CdZnTe wafer in the NH 4 F-based chemical contributed less to the leakage current compared to that passivated with the KOHbased solution [11]. In the present work, we present the analysis of Te and TeO 2 species on the surfaces of the CdZnTe wafers treated with hydrogen bromide and NH 4 F-based solutions, and the effects of the chemical treatments on leakage current and gamma-energy peak position.…”