TiO_2薄膜的硼掺杂对TiO_2/p~+-Si异质结器件电致发光的增强

利用磁控溅射在重掺硼硅(p+-Si)衬底上分别沉积TiO2薄膜和掺硼的TiO2(Ti O2∶B)薄膜,并经过氧气氛下600℃热处理,由此形成相应的TiO2/p+-Si和TiO2∶B/p+-Si异质结。与Ti O2/p+-Si异质结器件相比,TiO2∶B/p+-Si异质结器件的电致发光有明显的增强。分析认为:TiO2∶B薄膜经过热处理后,B原子进入TiO2晶格的间隙位,引入了额外的氧空位,而氧空位是TiO2/p+-Si异质结器件电致发光的发光中心,所以上述由B掺杂引起的氧空位浓度的增加是TiO2∶B/p+-Si异质结器件电致发光增强的原因。

Enhancement of Electroluminescence from TiO2/P+-Si Heterostructured-based Devices Through Boron-doping of TiO2 Films

TiO₂/p⁺-Si and TiO₂:B/p⁺-Si heterostructures were formed by sputtering TiO₂ films and boron-doped TiO₂ (TiO₂:B) films on heavily boron-doped silicon (p⁺-Si) substrates, respectively, followed by annealing at 600 ℃ in O₂ ambient. In contrast with the TiO₂/p⁺-Si heterostructured devices, the TiO₂:B/p⁺-Si counterpart exhibits markedly enhanced electroluminescence (EL). It is derived that the doped B atoms in TiO₂:B films enter into the interstitial sites of TiO₂ lattice after annealing at high temperature, which introduces excess oxygen vacancies. The increase of the concentration of oxygen vacancies due to B-doping leads to the enhancement of EL from the TiO₂:B/p⁺-Si heterostructured devices because oxygen vacancies are the light-emitting centers of the TiO₂/p⁺-Si heterostructured devices.