ZnO/Cu_2O异质结的制备及其光电性能研究

Cu_2O/ZnO Heterojunction Preparation and Photoelectrochemical Performance

通过两步法制备了由ZnO纳米棒阵列和Cu2O薄膜组成的异质结。首先利用低温湿化学法在掺氟的SnO2导电玻璃(比较FTO)上生长ZnO纳米棒阵列,然后在ZnO纳米棒阵列上通过水热法继续生长Cu2O薄膜,形成ZnO/Cu2O异质结。通过扫描电子显微镜和X射线衍射仪的表征结果得知,ZnO纳米棒阵列具有很好的c轴取向性,其长度为1μm;而Cu2O薄膜的厚度为1.5μm,其(111)面优先沿ZnO的(002)面外延生长。与ZnO纳米棒阵列相比,ZnO/Cu2O异质结在可见光范围内吸收强度明显增强。在模拟太阳光照射下(AM 1.5,100mW/cm2),由ZnO/Cu2O异质结构成的太阳能电池器件的开路电压为0.36V,短路电流密度为7.8mA/cm2,对应的填充因子为31%,光电转换效率为0.86%。

The heterojunction composed of Cu2O film and ZnO nanorod arrays was fabricated by a two-step method.ZnO nanorod arrays were firstly gr own on fluorine-doped SnO2 conducting glass（FTO） by chemical solution deposi tion method,then Cu2O film was deposited on ZnO nanorod arrays to form hetero junction by sequential hydrothermal method.The morphology and crystalline phase of obtained heterojunction were characterized by scanning electron microscope a nd X-ray diffraction.ZnO nanorod arrays had very high purity with a（002） orien tation and the length of the nanorod was around 1μm.The Cu2O film with a thi ckness of 1.5μm and a preferential（111） orientation grew on the ZnO nanorod a rrays.Compared with the ZnO nanorod arrays,Cu2O/ZnO heterojunction showed increased absorption intensity in the visible region.The Cu2O/ZnO heterojunc tion solar cells was observed under Sun illumination（AM 1.5,100 mW/cm2） wi th the short circuit current density（Jsc） of 7.8mA/cm2,the open circ uit voltage（Voc） of 0.36V,the filling factor（FF） of 0.31,and photovo ltaic conversion effciency（PCE） of 0.86%.