Cu2O-ZnO异质结具有成本低廉、环境友好及制备方法多样等优点,在太阳能电池领域有很好的应用前景。Cu2O薄膜的高电阻率和低载流子浓度是制约其效率提高的主要原因。本文采用磁控溅射法,在qV(Ar)∶qV(O2)=90∶0.3时得到单相p型Cu2O薄膜,电阻率为88.5Ω·cm,霍尔迁移率为16.9 cm2·V-1·s-1,载流子浓度为4.19×1015cm-3。并结合Cu2O-ZnO异质结能带结构的研究,对Cu2O-ZnO异质结太阳能电池今后的研究提出了一些建议。
Cu2O-ZnO heterojunction has shown great potential for photovoltaic application due to the low-cost,nontoxicity,abundance and variety of preparation methods.However,the resistivity of the Cu2O film in present ZnO-Cu2O heterojunction solar cell is relatively high,which seems to be the major problem for the low photoelectric conversion efficiency.Cu2O films were prepared using reactive direct current magnetron sputtering.The microstructures and properties were characterized using X-ray diffraction,X-ray photoelectron spectroscopy(XPS) and Hall-effect measurements.The influences of qV(Ar)∶qV(O2) on the structures and properties of deposited films were investigated.Single-phase Cu2O film with a resistivity of 88.5 Ω·cm,a Hall mobility of 16.9 cm2·V-1·s-1 and a carrier concentration of 4.19×1015 cm-3 were obtained at qV(Ar)∶qV(O2)=90∶0.3.The as-deposited Cu2O films have a great improvement in electrical performance and have more advantage in photovoltaic application compared with that prepared by electrochemical deposition or thermal oxidation.On that basis,the Cu2O-ZnO heterojunctions were fabricated in reversed growth sequence and the band alignments of the heterojunctions were given to investigate their potential application in solar cells.Possible areas for future work in this field were outlined and some suggestions were made based on our investigation of the Cu2O-ZnO heterojunctions fabricated by magnetron sputtering.