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We have already demonstrated that the graphitized mechanical pencil lead show superior field emission features in high emission current regime [1]. In this paper, we present the results of additional detailed analysis of field emission from completely graphitized pencil lead including Raman scattering, FIM/FEM images and energy distributions of emitted electrons as well as field emission characteristics also in low emission current regime. It is concluded again that the fully graphitized pencil lead is promising as low cost but superior field emitters

A prototype image sensor is developed using cadmium telluride-based photodiode and a volcano-structured FEA. Radiation tolerance of each component was tested by irradiating gamma-ray using cobalt-60 source. Gamma-ray tolerance of up to 1.2 MGy was confirmed for both FEA and photodiode.

The influences of gamma irradiation on CdS/CdTe photodiodes were investigated in order to evaluate their potential for applications to the radiation tolerant field emitter array (FEA) image sensor. It was found that the CdS/CdTe photodiodes have sufficient tolerance to high gamma-ray exposure more than 2 MGy. Furthermore, $I {-} V$ characteristics of CdS/CdTe photodiodes under gamma-ray irradiation were investigated. In the CdTe thickness of 6.5 $m\textbf{m}$, the change rate of current density increased with increase in the reverse bias voltage. On the other hand, in the case of 2.2 $m\textbf{m}$, the change rate of current density was almost constant irrespective of the reverse bias voltage. These results suggest that the increase in depletion layer width affects the change rate of current density.