热处理对ZnO六棱微管结构及发光特性的影响(英文)

Effects of Annealing on Structure and Luminescence of Hexagonal Zinc Oxide Microtubes

采用水热法在p-Si(111)衬底上生长出六棱ZnO微管,在空气中进行了300～600℃不同温度的热处理,并用XRD、XPS、PL谱研究了热处理对ZnO微管的结构、发光性能的影响。结果表明经过热处理后,ZnO微管的晶体质量显著改善。室温下的光致发光测试显示,在可见发射几乎消失的情况下,近带边发射的强度显著增大。与原位生长的ZnO微管相比,在泵浦密度为28kW/cm2时,热处理400℃的样品在近紫外区产生一个新的发射峰P。通过验证发射峰A与P之间的相对能量位置,认为新发射峰P可能是由激子-激子碰撞引起的。

Hexagonal ZnO microtubes were successfully grown on single crystal p-Si （111） substraies by hydrothermal method, and were annealed in air from 300℃ to 600 ℃. The effects of annealing on the structure and luminescence of ZnO microtubes were investigated by XRD, XPS and PL spectra. The results show the crystal quality of ZnO microtubes are markedly improved after annealing. The room-temperature photoluminescence spectra reveals that the intensity of near band-edge emission peaks increases obviously while the visible emission is almost quenched. By comparing with as-grown ZnO microtubes, a new emission peak P in the near-UV region is located for samples annealed at 400 ℃ with a pumping density as low as 28 kW/cm^2. The appearance of this new emission peak may be attributed to the exciton-exciton collision process by examining the relative energy positions between emission peak A and P.