退火对He注入及随后^(208)Pb^(27+)辐照的Al_2O_3单晶PL谱的影响

Effects of annealing on the photoluminescence of He ion implanted sapphire after 230-MeV Pb ion irradiation

利用高能离子研究了110keV的He+注入Al2O3单晶及随后230MeV的208Pb27+辐照并在不同温度条件下退火样品的光致发光的特性.从测试结果可以清楚地看到在375nm,390nm,413nm和450nm出现了强烈的发光峰.经过600K退火2h后测试结果显示,390nm发光峰增强剧烈,而别的发光峰显示不明显.在900K退火条件下,390nm的发光峰开始减弱相反在510nm出现了较强的发光峰,到1100K退火完毕后390nm的发光峰完全消失,而510nm的发光峰相对增强.从辐照样品的FTIR谱中看到,波数在460—510cm-1间的吸收是振动模式,经过离子辐照后,吸收带展宽,随着辐照量的增大,Al2O3振动吸收峰消失,说明Al2O3振动模式被完全破坏.1000—1300cm-1之间为Al-O-Al桥氧的伸缩振动模式,辐照后吸收带向高波数方向移动.退火后的FTIR谱变化不大.

Single crystal sapphire （Al2O3） samples implanted with 110 keV He and irradiated at 320 K by ^208Pb^27＋ ions with energy of 1.1 MeV/u to the fluences ranging from 1 × 10^12 to 5 × 10^14 ion/cm^2 and subsequently annealed at 600,900 and 1100 K. The obtained PL spectra showed that emission peaks centred at 375, 390, 413, and 450 nm appeared in irradiated samples. The peak of 390 nm became very intense after 600 K annealing. The peak of 390 nm weakened and 510 nm peak started to build up at 900 K annealing, the peak of 390 nm vanished and 510 nm peak increased with the annealing temperature rising to 1100 K. Infrared spectra showed a broadening of the absorption band between 460 cm^- 1, and 510 cm^- 1 indicating strongly damaged regions being formed in the Al2O3 samples and position shift of the absorption band at 1000-1300 cm^-1 towards higher wavenumber after Pb irradiation.