Preparation And Photoelectric Properties Of Cu₃P

Cuprous phosphide（Cu₃P）particles with excellent catalytic and fluxing properties have been widely applied in the fields of catalysts and copper welding.Reported results show that Cu₃P has a narrow band-gap,indicating Cu₃P could be used in the light detection,which has not attracted attention.Cu₃P are commonly in the form of particles.In order to obtain the photoelectric properties of Cu₃P,it is necessary to prepare Cu₃P thin film.In this paper,the preparation of Cu₃P thin films was first investigated.Intrinsic Cu₃P shows p-type characteristics.Then,the preparation of n-type Cu₃P was studied.Finally,the photoelectric properties of Cu₃P film and Cu₃P based materials are studied.The main contents and results are as follows:（1）Preparation,characterization and basic properties of p-Cu₃P films.First,Cu₃P thin films were prepared by phosphating with sodium hypophosphite and copper foil as precursors on copper substrate（Cu₃P/Cu）.The crystal quality can be improved by annealing.Optical band gap was measured to be 0.85 e V.Secondly,Cu₃P nano films with a thickness of 4-7 nm were deposited on the surface of silicon（with a layer of oxide）substrate,which put far away from the precursor.Then,the conductive type of Cu₃P was tested by hot probe method.Cu₃P showed p-type properties.In addition,the resistance was measured.It is found that the resistance increases with the rise of temperature,showing a positive temperature coefficient.Finally,the stability of Cu₃P was tested.Cu₃P can be oxidized at temperatures higher than 50℃,indicating that Cu₃P is not stable at higher temperature.In addition,Cu₃P was found to be unstable in acid or base solution.（2）Preparation and characterization of n-Cu₃P films.To prepare n-type Cu₃P,Zn O film was first deposited onto the surface of Cu₃P/Cu by magnetron sputtering.Then,the product obtained above was annealed.The n-type properties were tested by both hot probe method and Hall effect.The mechanism of transition from p-type to n-type was discussed.（3）Photoelectric properties of Cu₃P and Cu₃P based on materials.The photoelectric properties of p-Cu₃P,n-Cu₃P,Cu₃P-Zn O composites,p-Cu₃P/PMMA/n-ITO and Ag/Cu₃P were studied.All the above materials showed photocurrent under808 nm laser illumination.The results are as follows:（a）As the increase of light intensity increases from 0 lux to 14610 lux,the photocurrent of p-Cu₃P increases from12.57 m A to 25.33 m A.（b）The photoelectric response of n-Cu₃P is ten times higher than that of p-Cu₃P.（c）Cu₃P-Zn O compound was prepared and its photoelectric properties investigated.Cu₃P-Zn O annealed at 850℃has highest on/off ratio,photocurrent and photovoltage.However,the photoelectric response is slightly lower than that of the pure p-Cu₃P.（d）P-Cu₃P/PMMA/n-ITO and Ag/p-Cu₃P were prepared and their photoelectric properties investigated.P-Cu₃P/PMMA/n-ITO and Ag/p-Cu₃P showed rectification characteristics.Compared with p-Cu₃P,the On/Off ratio of P-Cu₃P/PMMA/n-ITO and Ag/p-Cu₃P is increased by about 1.8 times and 1.1 times,and the photocurrent is increased by about 3.2 times and 1.8 times,and the photovoltage is increased by about 2.9 times and 2.6 times,respectively.In addition,the photoelectric response of p-Cu₃P/PMMA/n-ITO is significantly faster than that of p-Cu₃P and Ag/p-Cu₃P.