Manhee Jeong

Growth and fabrication method of CdTe and its performance as a radiation detector

A CdTe crystal ingot doped with 2000 ppm of Cl was grown by using the low-pressure Bridgman (LPB) method at the Korea Atomic Energy Research Institute (KAERI). A Semiconductor detector as a radiation detection sensor with a size of 7 (W) × 6.5 (D) × 2 (H) mm3 was fabricated from the CdTe ingot. In addition, the properties of the CdTe sample were observed through four kinds of experiments to analyze its performance. The resistivity was obtained as 1.41 × 1010 Ωcm by using a Keithley 6517A high-precision electrometer. The mobility-lifetime products for electrons and holes were 3.137 × 10-4 cm2/V and 4.868 × 10-5 cm2/V, respectively. Finally, we achieved a 16.8% energy resolution at 59.5 keV for the 241Am gamma-ray source. The CdTe semiconductor detector grown at KAERI has a performance good enough to detect low-energy gamma-rays.

Characteristics of TlBr single crystals grown using the vertical Bridgman-Stockbarger method for semiconductor-based radiation detector applications

Abstract TlBr single crystals grown using the vertical Bridgman-Stockbarger method were characterized for semiconductor based radiation detector applications. It has been shown that the vertical Bridgman-Stockbarger method is effective to grow high-quality single crystalline ingots of TlBr. The TlBr single crystalline sample, which was located 6 cm from the tip of the ingot, exhibited lower impurity concentration, higher crystalline quality, high enough bandgap (>2.7 eV), and higher resistivity (2.5 × 1011 Ω·cm) which enables using the fabricated samples from the middle part of the TlBr ingot for fabricating high performance semiconductor radiation detectors.