Development of Heterojunction Diode-Type Gamma Ray Detectors Based on Epitaxially Grown Thick CdTe on$hboxn^+$-Si Substrates

Room temperature nuclear radiation detectors with energy discrimination capability developed by growing thick cadmium telluride (CdTe) epitaxial layers directly on n
⁺
-Si substrates in a metal-organic vapor phase epitaxy system is reported for the first time. The CdTe/n
⁺
-Si heterojunction diode detector exhibited good rectification and charge collection properties. The reverse leakage currents were typically 1times10
^-7
to 5times10
^-7
A/cm
²
at 50-V bias. The detector clearly demonstrated its energy discrimination capability by resolving gamma peak from the
²⁴¹
Am radioisotope during radiation detection test at room temperature