We have carried out an investigation of n+–p–p+ silicon diodes after irradiation with 1 MeV electrons and 10 MeV protons and subsequently after annealing. The effects upon the material and device parameters of samples irradiated with different particles are compared by expressing the particle fluence in terms of an effective absorbed dose of 1 MeV electrons. Although the spectrum of defects (observed by deep-level transient spectroscopy) introduced by 1 MeV electrons and 10 MeV protons was slightly different, the total defect introduction rate per effective 1 MeV electron dose was similar, as was the effect upon the device parameters. After irradiation with high fluences of electrons or protons, the effective carrier concentration in the base of the diodes was reduced dramatically, an effect referred to as “carrier removal.” The effects of carrier removal upon the device parameters, in particular, the series resistance and saturation current, are discussed in detail. In addition, the relative importance of different radiation-induced defects is compared.

Heavy doses of radiation in space can cause the failure of n+/p/p+ silicon solar cells due to the gradual introduction of compensating defects into the base layer of the diode. In this letter, we show that the radiation-induced defects, which play the most important role in this process, referred to as “carrier removal,” are probably minority-carrier traps at an energy level approximately 0.18 eV below the conduction band. We conclude that these defects must be positively charged before electron capture, and therefore, act as donor centers which compensate the p-type base layer.

Chitin is used in agriculture to improve crop production; however, its use is limited due to difficulties in its handling. A chitin nanofiber (CNF) overcomes this issue and, due to its elicitor activity, has great potential for crop protection. To expand CNF utilization, a copper nanoparticlesbased antimicrobic CNF (CuNPs/CNF) was prepared using a chemical reduction method. The formation of CuNPs was confirmed via scanning electron microscopy. Thermogravimetric analysis revealed that the amount of CuNPs on the CNF was dose-dependent on the precursor salt, copper acetate. CuNPs endowed the CNF with strong antimicrobial activity against Alternaria brassicicola and Pectobacterium carotovorum. Moreover, the CuNPs/CNF reduced pathogen infection in cabbage. The antimicrobial activity and disease prevention of the CuNPs/CNF was increased compared to the corresponding CNF or commercial agrochemical Bordeaux treatment. These results indicate that CuNPs conferred antimicrobial activity on the CNF and increased the efficacy of plant disease protection.

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