Passivation effect on Cd0.95Mn0.05Te0.98Se0.02 radiation detection performance

Y Kim; J Ko; J Byun; J Seo; B Park

doi:10.1016/j.apradiso.2023.110914

Passivation effect on Cd_0.95Mn_0.05Te_0.98Se_0.02 radiation detection performance

Appl Radiat Isot. 2023 Oct:200:110914. doi: 10.1016/j.apradiso.2023.110914. Epub 2023 Jun 27.

Authors

Y Kim¹, J Ko², J Byun³, J Seo³, B Park⁴

Affiliations

¹ Marine Radioactivity Monitoring Group, Korea Marine Environment Management Corporation, Busan 48931, Republic of Korea; Interdisciplinary Program in Precision Public Health, Korea university, Seoul 02841, Republic of Korea.
² Department of Chemistry, Konkuk University, Seoul 05029, Republic of Korea.
³ Interdisciplinary Program in Precision Public Health, Korea university, Seoul 02841, Republic of Korea; Department of Health and Safety Convergence Science, Korea university, Seoul 02841, Republic of Korea.
⁴ Interdisciplinary Program in Precision Public Health, Korea university, Seoul 02841, Republic of Korea; Department of Health and Safety Convergence Science, Korea university, Seoul 02841, Republic of Korea; Advanced Crystal Material/Device Research Center, Konkuk University, Seoul 143-701, Republic of Korea. Electronic address: pbj0116@korea.ac.kr.

PMID: 37423060
DOI: 10.1016/j.apradiso.2023.110914

Abstract

CdTe-based detectors have the problem of Te-rich surface layers caused by Br etching, which is one of fabrication steps. Te-rich layer acts as a trapping center and serves as an additional source of charge carriers, thereby degrading transport property of charge carriers and enriching leakage current on surface of detector. To solve this problem, we introduced sodium hypochlorite (NaOCl) as a passivant, and investigated its effect on Cd_0.95Mn_0.05Te_0.98Se_0.02 (CMTS), by analyzing chemical state of surface and its performance. After passivation with NaOCl, the results of X-ray photoelectron spectroscopy (XPS) shows the formation of tellurium oxide and elimination of water on CMTS surface, and CMTS presented enhanced performance with Am-241 radioisotope. Consequently, it is demonstrated that the passivation with NaOCl reduces leakage current, compensates defect, and elevates transport of charge carriers, thereby decreasing charge loss of carriers and improving performance of CMTS detector.

Keywords: CdMnTeSe; Charge collection efficiency; Passivation; Sodium hypochlorite; Surface recombination velocity.