Two kinds of Mg-Zn-Mn-Ca alloys with and without cerium were designed and fabricated. In-vitro degradation tests and electrochemical evaluations were carried out to compare their biocorrosion behavior in Hank's solution at 37 oC. After adding cerium, the continuous network distributed Ca2Mg6Zn3 phases in Mg-2Zn-0.5Mn-1Ca alloy(Alloy I) were separated due to the emerging non-continuously distributed Mg2 Ca phase and Mg12 Ce Zn phase. This change led to corrosion acceleration of Mg matrix at the initial stage but also sped up the formation of compact corrosion products for Mg-2Zn-0.5Mn-1Ca-1.5Ce alloy(Alloy II), and therefore enhanced its biocorrosion resistance. Cerium containing Alloy II has the potential to be used as future biomaterials.
In this paper,an InGaN metal-insulator-semiconductor(MIS) photodetector with an ultra-thin Al2O3 insulation layer deposited by atomic layer deposition(ALD) was studied.A high photoelectric responsivity of 0.25 A/W and a spectral responsivity rejection ratio of about three orders of magnitude at 1 V reverse bias were achieved for this MIS photodetector.The dominant carrier transport mechanism in the InGaN MIS photodetectors is submitted to the space charge limited current(SCLC) mechanism at high field and exhibits an Ohmic-like conduction at low electric field.The results indicate that the ultra-thin Al2O3 film deposited by the ALD technique can act as an excellent insulation dielectric for the InGaN photodetectors.
