Comparative study on the effects of chemical treatments on CdZnTe nuclear detectors

Abstract

Room temperature semiconductor detectors such as cadmium zinc telluride (CdZnTe) are often subject to surface damage during fabrication processes, thus affecting detector performance. The surface defects are usually removed through mechanical and chemical polishing, and passivation processes. This paper compares the effects of two surface passivation chemical solutions on CdZnTe detectors. The two chemicals studied are ammonium fluoride in hydrogen peroxide (NH 4 F + H 2 O 2 + H 2 O) and potassium hydroxide in hydrogen peroxide (0.1 g of KOH + 10 ml of 30% H 2 O 2 ) solutions. X-ray photoelectron spectroscopy analysis showed that the NH 4 F-based solution is more effective at converting Te species on the CZT wafer surfaces into a more stable TeO 2 layer, with values of 4.90 and 5.34 for the Te3d 3/2 O 2 /Te3d 3/2 and Te3d 5/2 O 2 /Te3d 5/2 peakheight ratios respectively, compared to the KOH-based solution which has 1.25 and 1.19 respectively. Analysis of the 59.5-keV peak of Am-241 showed that the sample passivated with the NH 4 F-based solution has a better energy resolution (FWHM = 9.83%) compared to the one passivated with the KOH-based solution (FWHM = 14.60%).

Carbon Nanotube Supported CdM(S, Se)/CdTe Anode Catalysts for Electrooxidation of Glucose in Alkaline Media

“…Two other peaks at binding energies at 577 and 585 eV indicate TeO x formation. [47] CV, CA, and EIS measurements were performed to examine the electrochemical performance of the catalysts. The catalytic activities of the catalysts were determined by CV analysis.…”

Perspective—Electrochemical Assessment of Slurry Formulations for Chemical Mechanical Planarization of Metals: Trends, Benefits and Challenges

“…2 Applications of metal CMP are not just limited to the field of microelectronics; they are routinely incorporated in the processing schemes of infrared detectors, 15 solar cell substrates, 16 flexible thinfilm transistors, 17 magnetic storage, 18 printed circuit boards 19 and nuclear detectors. 20 The present article, however, strictly focuses on the systems relevant for IC fabrications.…”

“…2 Applications of metal CMP are not just limited to the field of microelectronics; they are routinely incorporated in the processing schemes of infrared detectors, 15 solar cell substrates, 16 flexible thinfilm transistors, 17 magnetic storage, 18 printed circuit boards 19 and nuclear detectors. 20 The present article, however, strictly focuses on the systems relevant for IC fabrications.Aside from its technical challenges, advancement of fundamental CMP research is associated with many restrictions of proprietary information and patented product/protocol related confidentialities. Thus projections for future research-needs and selections of relevant test systems for laboratory scale studies largely rely on predictive assessments guided by the published literature.…”

EFFECT OF GAMMA IRRADIATION ON ELECTRICAL AND PHOTOELECTRICAL PROPERTIES OF Cd1-xMnxTe THIN FILMS

“…The dearth of larger volume CdTe/CZT single crystals must be resolved before their widespread application in nonproliferation inspections [1,2]. Recently, scientists at Brookhaven National Laboratory (BNL) developed a handheld gamma-ray spectrometer for nonproliferation inspections based on virtual Frisch-grid CZT detectors [1,2,[12][13][14][15][16]]. The whole system achieves an effective detection volume of 19.2 cm 3 , that is, 10 times larger than commercial co-planar grid (CPG) CZT detectors.…”

“…Until now, it was difficult to obtain CMT single crystals with high resistivity and acceptable carrier transport properties [1,2]. Some recent progress suggests the possibility of a breakthrough in this field, leading to large improvement in the performance of CMT radiation detectors [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. However, several material properties must be improved before CMT can be practically employed for X-ray and gamma-ray detections.…”