Joo-Hong Lee1,Jin-Wook Lee1
Sungkyunkwan University1
Joo-Hong Lee1,Jin-Wook Lee1
Sungkyunkwan University1
Reducing a crystal defect density is one of the critical issues for achieving high–performance perovskite optoelectronic devices. For devising effective mitigation strategies, it is imperative to accurately measure the defect density of perovskite thin films. Space–charge–limited current (SCLC) measurement has been commonly used to investigate the defect density of the perovskite thin films. In this study, we show that the physical vapor deposition process of the top metal contact generates unintended defects in underlying metal halide perovskite films to overestimate defect density by more than twofold during conventional SCLC measurement. We suggest an alternative metal contact approach to address this issue using van der Waals metal contact (vdWC) formed by transferring the physically laminated pre–deposited metal onto the perovskite layer. The vdWC approach enables formation of a defect–free metal/perovskite junction for accurate measurement of the defect density. The vdWC can also be a useful platform technology for development of high-performance and reliable electronic devices based on the perovskite thin films.