Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed ...Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12175131 and 11905133)the China Postdoctoral Science Foundation(Grant No.2021M692021)。
文摘Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.
