磁场下Bi-2223/Ag异质结的光伏效应研究

Photovoltaic Effect of Bi-2223/Ag Heterojunction in Magnetic Field

在连续紫色激光(λ=405nm)辐照下,30K到120K的温度范围内,对Bi-2223/Ag异质结在0T到9T的外加磁场作用下的光伏效应进行了研究。发现60K和120K的温度比较特殊,异质结在不同光强辐照下测得的开路电压(Voc)对外加磁场的变化基本无响应。经研究确认在外加磁场的作用下,60K以下时,Bi-2223/Ag异质结的内建电场源于金属与超导体之间的临近效应。其方向由超导体指向金属银电极。120K以上时,异质结的内建电场源于金属与超导体之间形成的类P-N结,方向由金属银电极指向超导体。60K到120K之间的温度范围内,内建电场源于临近效应和类P-N结两种机制的竞争。

Photovoltaic effects of Bi-2223 /Ag heterojunction under external magnetic fields from 0 T to 9 T induced by continuous purple-laser (λ=405 nm) irradiation have been investigated in the temperature range between 30 K and 120 K. There are two critical temperatures both 60 K and 120 K that the open circuit voltage ( V oc ) of Bi-2223 /Ag heterojunction is independent of magnetic field under different illumination. Make sure that the origin of the built-in electric field is a result of the Proximity effect for Bi-2223 /Ag heterojunction under external magnetic field below 60 K. The direction of the field is pointing from the superconductor to the silver electrode. There exists a built-in electrical field at the interface of sample above 120 K,similar to P-N junction,which the direction of interface field pointing from silver electrode to superconductor. From 60 K to 120 K,the built-in electric field originates from competition between the Proximity effect and quasi P-N junction in Bi-2223 /Ag heterojunction.