Do's and Don’ts of SCLC Analysis for Perovskite Materials

The space-charge-limited current (SCLC) measurement is one of the most common methods used to study the mobility and defect density in semiconductors. This method has the advantage of separating the measurement of the material properties with respect to electron and hole by the use of single-carrier devices. The apparent simplicity of the method made it very popular in both organic and perovskite photovoltaic research communities.<br/>Here, we discuss the often overlooked pitfalls of SCLC analysis for perovskite materials.<br/>First, we introduce a revisited analysis of SCLC measurements on perovskite single-crystals to obtain its trap densities. In fact, simulations clearly show that the presence of mobile ions severely complicates the SCLC analysis. Therefore, we also propose pulsed-SCLC as a new measurement procedure that helps to reduce the impact of mobile ions. We also show that the use of full drift-diffusion fitting of the pulsed-SCLC data allows for more accurate measurements of the mobility but also of both trap and mobile ion densities.<br/>Secondly, we explore the many limitations of SCLC for thin-film perovskite devices. We discuss the importance of reporting the hysteresis, using the appropriate scan speed to do the measurement, and choosing the right charge transport layers. These seemingly experimental ‘details’ can have a strong influence on both the values of the defect density and the mobility extracted from the SCLC analysis.