Abstract

In this research, nanocoral (NC) film of TiO₂ was decorated with nitrogen-doped graphene quantum dots (NGQDs, average size of ∼ 9 nm) and photovoltaic properties were investigated for dye-sensitized solar cell application. TiO₂ NCs and NGQDs synthesized separately using the hydrothermal method and TiO₂ NCs were decorated with NGQD solution by spin coating. FESEM images prove that TiO₂ NCs are composed from nanorods, with an average diameter of about 60 nm. Optical characterization shows that the NGQDs are highly orange-luminescent (emission at 590 nm) and absorb UV and visible light photons. Using NGQDs together with N719 dye as co-sensitizers led to an improvement in efficiency of DSSC, as investigated by photoelectrical measurements. The experimental analysis reveals that this improvement arises from enhancement of charge separation and collection due to the cascaded energy levels because of presence of NGQDs. By addition of NGQDs into TiO₂ NC photoanode, we were able to increase the short-circuit current density and efficiency by 40% (from 12.61 to 17.65 mA/cm²) and 31% (from 5.72 to 7.49%), respectively.

中文翻译：

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橙色光致发光N掺杂石墨烯量子点可作为染料敏化太阳能电池的有效共敏剂

摘要

在这项研究中，用氮掺杂的石墨烯量子点（NGQD，平均尺寸约为9 nm）装饰TiO ₂的纳米珊瑚（NC）膜，并研究了染料敏化太阳能电池的光伏性能。采用水热法分别合成的TiO ₂ NCs和NGQDs和通过旋涂法用NGQD溶液修饰TiO ₂ NCs。FESEM图像证明TiO ₂NC由纳米棒组成，平均直径约为60 nm。光学表征表明，NGQD具有高度的橙色发光性（在590 nm处发射），并吸收UV和可见光光子。通过光电测量研究，将NGQD与N719染料一起用作增敏剂可提高DSSC的效率。实验分析表明，由于存在NGQD，由于级联能级，电荷分离和收集的增强引起了这种改进。通过在TiO ₂ NC光电阳极中添加NGQD ，我们能够将短路电流密度和效率分别提高40％（从12.61到17.65 mA / cm ²）和31％（从5.72到7.49％）。