Effect Of Different Electrode Characteristics On Photovoltaic Properties Of 0.3Pb (Mg_0.33Nb_0.67)O₃-0.7PbTiO₃

0.3Pb(Mg_0.33Nb_0.67)O₃-0.7PbTiO₃（PMN-PT）is a typical perovskite type ferroelectric with high spontaneous polarization and photogenerated voltage free from material intrinsic band advantages such as gap effects.The open circuit voltage of a ferroelectric is high,but it produces a weak short circuit current.In order to achieve greater performance and reflect higher value,it is important to improve the short-circuit current of ferroelectric photovoltaic devices.Based on this problem,this paper will explore ways to improve the short-circuit current method after PMN-PT polarization.In this thesis,a semiconductor thin film electrode is used to collect carriers,and the semiconductor is used to alleviate the shielding problem of the surface bound charge of the ferroelectric single crystal after polarization.The main research contents are as follows:Firstly,the effect of metal electrodes on the photovoltaic properties of PMN-PT was investigated.PMN-PT was found to have good photovoltaic and ferroelectric properties,with a maximum open circuit voltage of-0.9 V and a short circuit current density of 146 nA/cm².This is due to the difference in the work function of the gold electrode（work function is 5.1 eV）and the silver electrode（work function is 4.26 eV）.Secondly,the effect of p-type semiconductor SnSe thin film electrode（work function 4.37 eV）and silver electrode（work function 4.26 eV）on the photovoltaic properties of PMN-PT was studied.The maximum open circuit voltage of PMN-PT was found to be-1 V and the short circuit current density was 100 nA/cm².It is shown that the carrier collection ability is independent of the hole concentration and is related to the difference in the work function of the two electrodes.Thirdly,the effect of n-type semiconductor SnSe₂ thin film electrode（work function is 5.54 eV）and Ag electrode（work function 4.26 eV）on the photovoltaic properties of PMN-PT was studied.It is found that the maximum open circuit voltage of PMN-PT is-1.2 V and the short-circuit current density is 627 nA/cm²,which indicates that the larger the difference of work function between the two electrodes,the higher the short-circuit current density,and can effectively weaken the PMN-PT surface bound charge after polarization.Shielding effect.Finally,the effect of two-layer semiconductor thin film electrodes on the photovoltaic properties of PMN-PT was investigated.The maximum open circuit voltage of PMN-PT was found to be-2.3 V,and the short-circuit current density was 229 nA/cm²,further indicating that the smaller the difference in work function between the two electrodes,the weaker the ability to collect carriers.