CdS纳米晶敏化ZnO/Cu_2O异质结太阳能电池的研究

Study on ZnO/Cu_2O heterojunction solar cells by CdS nanocrystalline sensitization

为了研究CdS纳米晶对ZnO/Cu_2O异质结太阳能电池性能的影响,利用湿化学法在FTO玻璃基底上制备了高度规整的ZnO纳米棒阵列,并用CdS纳米晶对ZnO纳米棒阵列进行敏化;采用磁控溅射法在敏化后的ZnO纳米棒阵列表面沉积Cu_2O薄膜,组装成ZnO/Cu_2O异质结太阳能电池。分别用X射线衍射(XRD)仪、扫描电镜(SEM)、紫外可见分光(UV-vis)光度计和光电性能综合测试仪对物相、形貌、吸收光谱和光电性能进行了表征。研究结果表明:ZnO纳米棒为六方纤锌矿结构,其直径约80~100nm,长约2μm,棒间距约100~120nm;Cu_2O团簇颗粒直径约为100~300nm,形成致密膜层并紧密覆盖在ZnO纳米棒阵列表面上,构成ZnO/Cu_2O异质结结构;经CdS纳米晶敏化的ZnO/Cu_2O异质结在可见光范围内吸收强度明显增强,其中ZnO+9CdS+Cu_2O异质结性能最好,其对应的太阳能电池在模拟太阳光下,开路电压为0.524V,短路电流密度为7.18mA·cm^(-2),填充因子为41%,转化效率达1.57%。

In order to study ZnO/Cu2 O heteroj unction solar cells by CdS nanocrystalline sensitization, the fabrication of ZnO nanorod arrays on the FTO-glass substrates,CdS nanocrystalline on the ZnO nanorod arrays as visible light sensitizer,Cue O film on the ZnO nanorod arrays before and after the combination with CdS nanocrystalline,and the assembling of ZnO/Cue O heterojunction solar cells were carried out in this paper. The crystal phase,morphology, UV-vis absorbance spectra and comprehensive photoelectric performance were characterized by X-ray diffraction （XRD）,scanning electron microscopy （SEM）,UV- vis spectrophotometer and comprehensive photoelectric device, respectively. The results show that ZnO nanorods are wurtzite structure in phase and are about 80--100 nm in diameter,2μm in length and 100 --120 nm in rod interval distance. The Cue 0 particles, which are the cubic phase, are about 100--300 nm in grain diameter and form a dense membrane layer on the ZnO nanorod arrays,which construct the ZnO/Cu2 O heterojunction structure. Furthermore,it is also found that the CdS nanocrystlline could well sensitize the ZnO/Cu2O heterojunction structures in the visible region. Among them, the performance of ZnO＋9CdS＋Cu2O heterojunction structure is optimal. And in simulated sunlight, the solar cell with ZnO＋ 9CclS＋ Cu2 O heterojunction structure can achieve an open-circuit voltage of 0. 524 V, a short-cir- cuit current density of 7.18 mA . cm-2, a fill factor of 41% and a overall light to electricity conversion efficiency of 1.57%.