Study On Antistatic Aluminum-doped Zinc Oxide Pigment And Its Proton Dadition Effect

The ZnO-type thermal control coatings possessing low ratio of solar absorptance to emittance factor are commonly used for spacecraft. And possess excellent optical properties. But under the exposure of space charging environment, spacecraft will badly damaged by charging and discharge. Using rational modification technique can alleviate or avoid the problem of its safety under space environment. On condition that keeping their initial optical properties .which have significant applied background in engineering and research meaning in theory.In this paper, we used Sol-Gel technology and solid state method, where Al(C₃H₇O)₃ was used as the dopant,ammonia as the catalyst, to do research on the technique of coating modification of ZnO pigments used by spacecraft. The effects of Al dopant concentration,thermal treatment temperature and time, annealing temperature,annealing time on the resistivity and optical properties were studied. Furthmore, we did investigation on the damage mechanism of modified pigments under the protons irradiation.After optimizing the technologic conditions, The results indicated that when the Al concentration was 3at%, the post heat cheating was 900℃and calcined 3 hours, annealing temperature was 800℃and annealing time was 1.5 hour, The resistivity of Al-doped ZnO pigments was decreased form 108?.cm to 105?.cm, meanwhile the solar absorptance were increased form 0.149 to 0.188, which changed about 0.039 can used as the pigment of antistatic thermal control coatings.Under the protons irradiation,optical degradation of the modified pigment occurred mainly in visible region. The main absorption peak was the same as before irradiation.Δαs of the modified ZnO pigments became bigger than that of the unmodified.Photoluminescence(PL) spectral analysis indicate that,before and after proton irradiation, the type of point defects in modified ZnO pigments were the same to pure ZnO pigments, included zinc interstitial (Zni), oxygen interstitial (Oi), zinc vacancies (VZn), and oxygen vacancies (VO). In addition, there existed no new type of point defects.