/spl gamma/-radiation dosimeter using the optical and electrical properties of Al/S/CuPc/Al thin films

Thermally evaporated thin film pn-junctions with a metal/sulfur/copperphthalocyanine/ metal structure were fabricated and the effects of /spl gamma/-radiation on their optical and electrical properties were investigated for the purpose of dosimetry applications. The optical band gap showed slight changes in value when irradiated. The as-deposited and irradiated Al/S/CuPc/Al devices demonstrated Zener diode breakdown under reverse bias voltage and a space-charge-limited conduction mechanism under forward bias. The absorbance, the density of colour centre and Zener breakdown current exhibited a highly consistent linear response to /spl gamma/-radiation exposure. However, the best fit for the experimental data was obtained using the Zener breakdown current for /spl gamma/-ray dose assessment.