Perovskite materials show excellent photovoltaic effect and absorption properties, but because it contains lead, environmental issues regarding its applications are always raised. A team of Korean researchers at Chung-Ang University (CAU) and Sungkyunkwan University (SKKU) report the development of the non-toxic leak-free tin-based perovksite materials for efficient photodetector. The study appears in the journal Advanced Functional Materials in December and is selected as a front-cover image of the journal.

Lead-based perovskite materials not only have environmental problems, but also exhibit a limited light absorption of only the visible light region. In addition, since they cause noise generation due to low bond strength between lead and halogen ions, it is necessary to introduce new perovskite materials to replace the lead-based perovskite.

In order to solve the problems of lead-based perovskite, non-lead-based perovskite material as an effective photosensitive layer to avoid the harmfulness of lead and improve the detection performance was developed by the team that Dr. Woongsik Jang (CAU), Dr. Kyusun Kim (SKKU), Prof. Il Jeon (SKKU), and Prof. Dong Hwan Wang (CAU) participated in.

Prof. D. H. Wang said that “The tin-based perovskite material suppresses the separation of internal ions through strong bond strength between tin and halogen ions, and reduces the generation of noise signals.” “Consequently, the lead-free perovskite photodetector exhibits a fast response speed, a wide response range, and higher detection performance. In particular, by analyzing the charge injection mechanism in the perovskite device, it was demonstrated that the injection barrier of the lead-free perovskite was effective in suppressing the dark current, which leads to excellent detection and fast response.”

Accordingly, by introducing excellent perovskite technology, it will be possible to lead the image sensor research field by maximizing the signal-to-noise ratio, photo-response speed under various illumination conditions.

[Reference] Woongsik Jang, Kyusun Kim, Byung Gi Kim, Jeong-Seok Nam, Il Jeon, and Dong Hwan Wang, “Prevention of Noise Current Generation in Tin-Based Lead-Free Perovskites for Highly Sensitive Photodetection”, Advanced Functional Materials, 2022, 32(51), 2207713, https://doi.org/10.1002/adfm.202207713

[Main Author] Woongsik Jang (Chung-Ang University), Kyusun Kim (Sungkyunkwan University), Il Jeon (Sungkyunkwan University), and Dong Hwan Wang (Chung-Ang University)

* Contact : Professor Dong Hwan Wang (king0401@cau.ac.kr)