N掺杂的ZnO薄膜发光性质研究

Investigation of Luminescence Properties in N-doped Thin Film

以醋酸锌为前驱体、醋酸铵为掺杂源，采用溶胶—凝胶法制备出N掺杂的ZnO薄膜，研究了其表面形貌、晶体结构和变温下的光致发光光谱，探讨了N作为受主掺杂的热力学性质。结果表明，掺杂后的薄膜是六角纤锌矿结构，光谱中表现出和N相关的受主束缚激子、自由激子一受主和施主一受主对发光现象。通过理论计算得到，N作为受主的电离能大小为0．255—0．310eV，表明N是一种有效的浅受主，其能级上的电子在较小的能量下就能够电离。

N-doped ZnO thin film was prepared by using sol-gel method,in which zinc acetate and ammonium acetate were used as precursor and dopant source, respectively. The surface morphology, crystal structure and variable-temperature photoluminescence （PL） spectra were studied. The thermodynamics properties of N acceptor were discussed. The results show that the N-doped ZnO thin film is of hexagonal wurtzite structure. The N-related acceptor bound exciton, free exciton-acceptor and donor-acceptor pair emissions are observed in PL spectra. The ionization energy of N acceptor obtained by theoretical calculation is 0.255~0.310 eV, which demonstrates that N is an effective shallow acceptor and the electrons in the level can be ionized under smaller energy.