[15p-B5-1~19] 7.2 Applications and technologies of electron beams

[15p-B5-16] I-V characteristics of CdTe/CdS photodiode for radiation tolerant FEA image sensor under gamma-ray irradiation

〇Tamotsu Okamoto¹, Tomoya Igari¹, Yasuhito Gotoh², Nobuhiro Sato², Masafumi Akiyoshi³, Ikuji Takagi² (1.NIT, Kisarazu Coll., 2.Kyoto Univ., 3.Osaka Pref. Univ.)

Keywords:CdTe, II-VI compounds, field emitter array

We proposed a compact image sensor that uses a combination of a matrix-driven Spindt-type field emitter array (FEA) and a CdTe-based photoconducting film. In this work, we investigated I-V characteristics of CdTe/CdS photodiode under gamma-ray irradiation. The structure of CdTe/CdS diode used in this work was glass / ITO / n-CdS / p-CdTe / carbon electrode. Thickness of CdTe was approximately 6.5 micrometer, and the area of the diode was 1 cm². The increase in current due to the gamma-ray absorption was observed. Furthermore, the increase rate in current at the voltage of -5 V was larger than that at zero bias. This result was probably due to increase in the depletion layer thickness by the reverse bias. The increase rate in current at the voltage of -5 V was approximately 220 nA/cm² per unit dose rate (1 kGy/h).